INTRODUCTION, paragraph 1: OLD: HTTPbis Working Group R. Fielding, Ed. Internet-Draft Adobe Obsoletes: 2616 (if approved) J. Reschke, Ed. Updates: 2817 (if approved) greenbytes Intended status: Standards Track May 6, 2014 Expires: November 7, 2014 NEW: Internet Engineering Task Force (IETF) R. Fielding, Ed. Request for Comments: 7231 Adobe Obsoletes: 2616 J. Reschke, Ed. Updates: 2817 greenbytes Category: Standards Track May 2014 ISSN: 2070-1721 INTRODUCTION, paragraph 2: OLD: Hypertext Transfer Protocol (HTTP/1.1): Semantics and Content draft-ietf-httpbis-p2-semantics-latest NEW: Hypertext Transfer Protocol (HTTP/1.1): Semantics and Content INTRODUCTION, paragraph 5: OLD: Editorial Note (To be removed by RFC Editor) Discussion of this draft takes place on the HTTPBIS working group mailing list (ietf-http-wg@w3.org), which is archived at . The current issues list is at and related documents (including fancy diffs) can be found at . The changes in this draft are summarized in Appendix E.4. Status of This Memo NEW: Status of This Memo INTRODUCTION, paragraph 6: OLD: This Internet-Draft is submitted in full conformance with the provisions of BCP 78 and BCP 79. NEW: This is an Internet Standards Track document. INTRODUCTION, paragraph 7: OLD: Internet-Drafts are working documents of the Internet Engineering Task Force (IETF). Note that other groups may also distribute working documents as Internet-Drafts. The list of current Internet- Drafts is at http://datatracker.ietf.org/drafts/current/. NEW: This document is a product of the Internet Engineering Task Force (IETF). It represents the consensus of the IETF community. It has received public review and has been approved for publication by the Internet Engineering Steering Group (IESG). Further information on Internet Standards is available in Section 2 of RFC 5741. INTRODUCTION, paragraph 8: OLD: Internet-Drafts are draft documents valid for a maximum of six months and may be updated, replaced, or obsoleted by other documents at any time. It is inappropriate to use Internet-Drafts as reference material or to cite them other than as "work in progress." This Internet-Draft will expire on November 7, 2014. NEW: Information about the current status of this document, any errata, and how to provide feedback on it may be obtained at http://www.rfc-editor.org/info/rfc7231. Section 11., paragraph 0: OLD: 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 6 1.1. Conformance and Error Handling . . . . . . . . . . . . . . 6 1.2. Syntax Notation . . . . . . . . . . . . . . . . . . . . . 6 2. Resources . . . . . . . . . . . . . . . . . . . . . . . . . . 7 3. Representations . . . . . . . . . . . . . . . . . . . . . . . 7 3.1. Representation Metadata . . . . . . . . . . . . . . . . . 8 3.1.1. Processing Representation Data . . . . . . . . . . . . 8 3.1.2. Encoding for Compression or Integrity . . . . . . . . 11 3.1.3. Audience Language . . . . . . . . . . . . . . . . . . 13 3.1.4. Identification . . . . . . . . . . . . . . . . . . . . 14 3.2. Representation Data . . . . . . . . . . . . . . . . . . . 17 3.3. Payload Semantics . . . . . . . . . . . . . . . . . . . . 17 3.4. Content Negotiation . . . . . . . . . . . . . . . . . . . 18 3.4.1. Proactive Negotiation . . . . . . . . . . . . . . . . 19 3.4.2. Reactive Negotiation . . . . . . . . . . . . . . . . . 20 4. Request Methods . . . . . . . . . . . . . . . . . . . . . . . 21 4.1. Overview . . . . . . . . . . . . . . . . . . . . . . . . . 21 4.2. Common Method Properties . . . . . . . . . . . . . . . . . 22 4.2.1. Safe Methods . . . . . . . . . . . . . . . . . . . . . 22 4.2.2. Idempotent Methods . . . . . . . . . . . . . . . . . . 23 4.2.3. Cacheable Methods . . . . . . . . . . . . . . . . . . 24 4.3. Method Definitions . . . . . . . . . . . . . . . . . . . . 24 4.3.1. GET . . . . . . . . . . . . . . . . . . . . . . . . . 24 4.3.2. HEAD . . . . . . . . . . . . . . . . . . . . . . . . . 25 4.3.3. POST . . . . . . . . . . . . . . . . . . . . . . . . . 25 4.3.4. PUT . . . . . . . . . . . . . . . . . . . . . . . . . 26 4.3.5. DELETE . . . . . . . . . . . . . . . . . . . . . . . . 29 4.3.6. CONNECT . . . . . . . . . . . . . . . . . . . . . . . 30 4.3.7. OPTIONS . . . . . . . . . . . . . . . . . . . . . . . 31 4.3.8. TRACE . . . . . . . . . . . . . . . . . . . . . . . . 32 5. Request Header Fields . . . . . . . . . . . . . . . . . . . . 33 5.1. Controls . . . . . . . . . . . . . . . . . . . . . . . . . 33 5.1.1. Expect . . . . . . . . . . . . . . . . . . . . . . . . 34 5.1.2. Max-Forwards . . . . . . . . . . . . . . . . . . . . . 36 5.2. Conditionals . . . . . . . . . . . . . . . . . . . . . . . 36 5.3. Content Negotiation . . . . . . . . . . . . . . . . . . . 37 5.3.1. Quality Values . . . . . . . . . . . . . . . . . . . . 37 5.3.2. Accept . . . . . . . . . . . . . . . . . . . . . . . . 38 5.3.3. Accept-Charset . . . . . . . . . . . . . . . . . . . . 40 5.3.4. Accept-Encoding . . . . . . . . . . . . . . . . . . . 41 5.3.5. Accept-Language . . . . . . . . . . . . . . . . . . . 42 5.4. Authentication Credentials . . . . . . . . . . . . . . . . 43 5.5. Request Context . . . . . . . . . . . . . . . . . . . . . 44 5.5.1. From . . . . . . . . . . . . . . . . . . . . . . . . . 44 5.5.2. Referer . . . . . . . . . . . . . . . . . . . . . . . 45 5.5.3. User-Agent . . . . . . . . . . . . . . . . . . . . . . 46 6. Response Status Codes . . . . . . . . . . . . . . . . . . . . 47 6.1. Overview of Status Codes . . . . . . . . . . . . . . . . . 48 6.2. Informational 1xx . . . . . . . . . . . . . . . . . . . . 50 6.2.1. 100 Continue . . . . . . . . . . . . . . . . . . . . . 50 6.2.2. 101 Switching Protocols . . . . . . . . . . . . . . . 50 6.3. Successful 2xx . . . . . . . . . . . . . . . . . . . . . . 51 6.3.1. 200 OK . . . . . . . . . . . . . . . . . . . . . . . . 51 6.3.2. 201 Created . . . . . . . . . . . . . . . . . . . . . 52 6.3.3. 202 Accepted . . . . . . . . . . . . . . . . . . . . . 52 6.3.4. 203 Non-Authoritative Information . . . . . . . . . . 52 6.3.5. 204 No Content . . . . . . . . . . . . . . . . . . . . 53 6.3.6. 205 Reset Content . . . . . . . . . . . . . . . . . . 53 6.4. Redirection 3xx . . . . . . . . . . . . . . . . . . . . . 54 6.4.1. 300 Multiple Choices . . . . . . . . . . . . . . . . . 55 6.4.2. 301 Moved Permanently . . . . . . . . . . . . . . . . 56 6.4.3. 302 Found . . . . . . . . . . . . . . . . . . . . . . 56 6.4.4. 303 See Other . . . . . . . . . . . . . . . . . . . . 57 6.4.5. 305 Use Proxy . . . . . . . . . . . . . . . . . . . . 57 6.4.6. 306 (Unused) . . . . . . . . . . . . . . . . . . . . . 57 6.4.7. 307 Temporary Redirect . . . . . . . . . . . . . . . . 58 6.5. Client Error 4xx . . . . . . . . . . . . . . . . . . . . . 58 6.5.1. 400 Bad Request . . . . . . . . . . . . . . . . . . . 58 6.5.2. 402 Payment Required . . . . . . . . . . . . . . . . . 58 6.5.3. 403 Forbidden . . . . . . . . . . . . . . . . . . . . 58 6.5.4. 404 Not Found . . . . . . . . . . . . . . . . . . . . 59 6.5.5. 405 Method Not Allowed . . . . . . . . . . . . . . . . 59 6.5.6. 406 Not Acceptable . . . . . . . . . . . . . . . . . . 59 6.5.7. 408 Request Timeout . . . . . . . . . . . . . . . . . 60 6.5.8. 409 Conflict . . . . . . . . . . . . . . . . . . . . . 60 6.5.9. 410 Gone . . . . . . . . . . . . . . . . . . . . . . . 60 6.5.10. 411 Length Required . . . . . . . . . . . . . . . . . 61 6.5.11. 413 Payload Too Large . . . . . . . . . . . . . . . . 61 6.5.12. 414 URI Too Long . . . . . . . . . . . . . . . . . . . 61 6.5.13. 415 Unsupported Media Type . . . . . . . . . . . . . . 61 6.5.14. 417 Expectation Failed . . . . . . . . . . . . . . . . 62 6.5.15. 426 Upgrade Required . . . . . . . . . . . . . . . . . 62 6.6. Server Error 5xx . . . . . . . . . . . . . . . . . . . . . 62 6.6.1. 500 Internal Server Error . . . . . . . . . . . . . . 62 6.6.2. 501 Not Implemented . . . . . . . . . . . . . . . . . 63 6.6.3. 502 Bad Gateway . . . . . . . . . . . . . . . . . . . 63 6.6.4. 503 Service Unavailable . . . . . . . . . . . . . . . 63 6.6.5. 504 Gateway Timeout . . . . . . . . . . . . . . . . . 63 6.6.6. 505 HTTP Version Not Supported . . . . . . . . . . . . 63 7. Response Header Fields . . . . . . . . . . . . . . . . . . . . 64 7.1. Control Data . . . . . . . . . . . . . . . . . . . . . . . 64 7.1.1. Origination Date . . . . . . . . . . . . . . . . . . . 64 7.1.2. Location . . . . . . . . . . . . . . . . . . . . . . . 68 7.1.3. Retry-After . . . . . . . . . . . . . . . . . . . . . 69 7.1.4. Vary . . . . . . . . . . . . . . . . . . . . . . . . . 70 7.2. Validator Header Fields . . . . . . . . . . . . . . . . . 71 7.3. Authentication Challenges . . . . . . . . . . . . . . . . 72 7.4. Response Context . . . . . . . . . . . . . . . . . . . . . 72 7.4.1. Allow . . . . . . . . . . . . . . . . . . . . . . . . 72 7.4.2. Server . . . . . . . . . . . . . . . . . . . . . . . . 73 8. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 73 8.1. Method Registry . . . . . . . . . . . . . . . . . . . . . 74 8.1.1. Procedure . . . . . . . . . . . . . . . . . . . . . . 74 8.1.2. Considerations for New Methods . . . . . . . . . . . . 74 8.1.3. Registrations . . . . . . . . . . . . . . . . . . . . 75 8.2. Status Code Registry . . . . . . . . . . . . . . . . . . . 75 8.2.1. Procedure . . . . . . . . . . . . . . . . . . . . . . 75 8.2.2. Considerations for New Status Codes . . . . . . . . . 76 8.2.3. Registrations . . . . . . . . . . . . . . . . . . . . 76 8.3. Header Field Registry . . . . . . . . . . . . . . . . . . 77 8.3.1. Considerations for New Header Fields . . . . . . . . . 78 8.3.2. Registrations . . . . . . . . . . . . . . . . . . . . 80 8.4. Content Coding Registry . . . . . . . . . . . . . . . . . 80 8.4.1. Procedure . . . . . . . . . . . . . . . . . . . . . . 81 8.4.2. Registrations . . . . . . . . . . . . . . . . . . . . 81 9. Security Considerations . . . . . . . . . . . . . . . . . . . 81 9.1. Attacks Based On File and Path Names . . . . . . . . . . . 82 9.2. Attacks Based On Command, Code, or Query Injection . . . . 82 9.3. Disclosure of Personal Information . . . . . . . . . . . . 83 9.4. Disclosure of Sensitive Information in URIs . . . . . . . 83 9.5. Disclosure of Fragment after Redirects . . . . . . . . . . 83 9.6. Disclosure of Product Information . . . . . . . . . . . . 84 9.7. Browser Fingerprinting . . . . . . . . . . . . . . . . . . 84 10. Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . 85 11. References . . . . . . . . . . . . . . . . . . . . . . . . . . 85 11.1. Normative References . . . . . . . . . . . . . . . . . . . 85 11.2. Informative References . . . . . . . . . . . . . . . . . . 86 Appendix A. Differences between HTTP and MIME . . . . . . . . . . 88 A.1. MIME-Version . . . . . . . . . . . . . . . . . . . . . . . 89 A.2. Conversion to Canonical Form . . . . . . . . . . . . . . . 89 A.3. Conversion of Date Formats . . . . . . . . . . . . . . . . 89 A.4. Conversion of Content-Encoding . . . . . . . . . . . . . . 90 A.5. Conversion of Content-Transfer-Encoding . . . . . . . . . 90 A.6. MHTML and Line Length Limitations . . . . . . . . . . . . 90 Appendix B. Changes from RFC 2616 . . . . . . . . . . . . . . . . 90 Appendix C. Imported ABNF . . . . . . . . . . . . . . . . . . . . 93 Appendix D. Collected ABNF . . . . . . . . . . . . . . . . . . . 93 Appendix E. Change Log (to be removed by RFC Editor before publication) . . . . . . . . . . . . . . . . . . . . 96 E.1. Since RFC 2616 . . . . . . . . . . . . . . . . . . . . . . 96 E.2. Since draft-ietf-httpbis-p2-semantics-24 . . . . . . . . . 96 E.3. Since draft-ietf-httpbis-p2-semantics-25 . . . . . . . . . 97 E.4. Since draft-ietf-httpbis-p2-semantics-26 . . . . . . . . . 97 Index . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 97 NEW: 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 6 1.1. Conformance and Error Handling . . . . . . . . . . . . . . 6 1.2. Syntax Notation . . . . . . . . . . . . . . . . . . . . . 6 2. Resources . . . . . . . . . . . . . . . . . . . . . . . . . . 7 3. Representations . . . . . . . . . . . . . . . . . . . . . . . 7 3.1. Representation Metadata . . . . . . . . . . . . . . . . . 8 3.1.1. Processing Representation Data . . . . . . . . . . . . 8 3.1.2. Encoding for Compression or Integrity . . . . . . . . 11 3.1.3. Audience Language . . . . . . . . . . . . . . . . . . 13 3.1.4. Identification . . . . . . . . . . . . . . . . . . . . 14 3.2. Representation Data . . . . . . . . . . . . . . . . . . . 17 3.3. Payload Semantics . . . . . . . . . . . . . . . . . . . . 17 3.4. Content Negotiation . . . . . . . . . . . . . . . . . . . 18 3.4.1. Proactive Negotiation . . . . . . . . . . . . . . . . 19 3.4.2. Reactive Negotiation . . . . . . . . . . . . . . . . . 20 4. Request Methods . . . . . . . . . . . . . . . . . . . . . . . 21 4.1. Overview . . . . . . . . . . . . . . . . . . . . . . . . . 21 4.2. Common Method Properties . . . . . . . . . . . . . . . . . 22 4.2.1. Safe Methods . . . . . . . . . . . . . . . . . . . . . 22 4.2.2. Idempotent Methods . . . . . . . . . . . . . . . . . . 23 4.2.3. Cacheable Methods . . . . . . . . . . . . . . . . . . 24 4.3. Method Definitions . . . . . . . . . . . . . . . . . . . . 24 4.3.1. GET . . . . . . . . . . . . . . . . . . . . . . . . . 24 4.3.2. HEAD . . . . . . . . . . . . . . . . . . . . . . . . . 25 4.3.3. POST . . . . . . . . . . . . . . . . . . . . . . . . . 25 4.3.4. PUT . . . . . . . . . . . . . . . . . . . . . . . . . 26 4.3.5. DELETE . . . . . . . . . . . . . . . . . . . . . . . . 29 4.3.6. CONNECT . . . . . . . . . . . . . . . . . . . . . . . 30 4.3.7. OPTIONS . . . . . . . . . . . . . . . . . . . . . . . 31 4.3.8. TRACE . . . . . . . . . . . . . . . . . . . . . . . . 32 5. Request Header Fields . . . . . . . . . . . . . . . . . . . . 33 5.1. Controls . . . . . . . . . . . . . . . . . . . . . . . . . 33 5.1.1. Expect . . . . . . . . . . . . . . . . . . . . . . . . 34 5.1.2. Max-Forwards . . . . . . . . . . . . . . . . . . . . . 36 5.2. Conditionals . . . . . . . . . . . . . . . . . . . . . . . 36 5.3. Content Negotiation . . . . . . . . . . . . . . . . . . . 37 5.3.1. Quality Values . . . . . . . . . . . . . . . . . . . . 37 5.3.2. Accept . . . . . . . . . . . . . . . . . . . . . . . . 38 5.3.3. Accept-Charset . . . . . . . . . . . . . . . . . . . . 40 5.3.4. Accept-Encoding . . . . . . . . . . . . . . . . . . . 41 5.3.5. Accept-Language . . . . . . . . . . . . . . . . . . . 42 5.4. Authentication Credentials . . . . . . . . . . . . . . . . 43 5.5. Request Context . . . . . . . . . . . . . . . . . . . . . 44 5.5.1. From . . . . . . . . . . . . . . . . . . . . . . . . . 44 5.5.2. Referer . . . . . . . . . . . . . . . . . . . . . . . 45 5.5.3. User-Agent . . . . . . . . . . . . . . . . . . . . . . 46 6. Response Status Codes . . . . . . . . . . . . . . . . . . . . 47 6.1. Overview of Status Codes . . . . . . . . . . . . . . . . . 48 6.2. Informational 1xx . . . . . . . . . . . . . . . . . . . . 50 6.2.1. 100 Continue . . . . . . . . . . . . . . . . . . . . . 50 6.2.2. 101 Switching Protocols . . . . . . . . . . . . . . . 50 6.3. Successful 2xx . . . . . . . . . . . . . . . . . . . . . . 51 6.3.1. 200 OK . . . . . . . . . . . . . . . . . . . . . . . . 51 6.3.2. 201 Created . . . . . . . . . . . . . . . . . . . . . 52 6.3.3. 202 Accepted . . . . . . . . . . . . . . . . . . . . . 52 6.3.4. 203 Non-Authoritative Information . . . . . . . . . . 52 6.3.5. 204 No Content . . . . . . . . . . . . . . . . . . . . 53 6.3.6. 205 Reset Content . . . . . . . . . . . . . . . . . . 53 6.4. Redirection 3xx . . . . . . . . . . . . . . . . . . . . . 54 6.4.1. 300 Multiple Choices . . . . . . . . . . . . . . . . . 55 6.4.2. 301 Moved Permanently . . . . . . . . . . . . . . . . 56 6.4.3. 302 Found . . . . . . . . . . . . . . . . . . . . . . 56 6.4.4. 303 See Other . . . . . . . . . . . . . . . . . . . . 57 6.4.5. 305 Use Proxy . . . . . . . . . . . . . . . . . . . . 57 6.4.6. 306 (Unused) . . . . . . . . . . . . . . . . . . . . . 57 6.4.7. 307 Temporary Redirect . . . . . . . . . . . . . . . . 58 6.5. Client Error 4xx . . . . . . . . . . . . . . . . . . . . . 58 6.5.1. 400 Bad Request . . . . . . . . . . . . . . . . . . . 58 6.5.2. 402 Payment Required . . . . . . . . . . . . . . . . . 58 6.5.3. 403 Forbidden . . . . . . . . . . . . . . . . . . . . 58 6.5.4. 404 Not Found . . . . . . . . . . . . . . . . . . . . 59 6.5.5. 405 Method Not Allowed . . . . . . . . . . . . . . . . 59 6.5.6. 406 Not Acceptable . . . . . . . . . . . . . . . . . . 59 6.5.7. 408 Request Timeout . . . . . . . . . . . . . . . . . 60 6.5.8. 409 Conflict . . . . . . . . . . . . . . . . . . . . . 60 6.5.9. 410 Gone . . . . . . . . . . . . . . . . . . . . . . . 60 6.5.10. 411 Length Required . . . . . . . . . . . . . . . . . 61 6.5.11. 413 Payload Too Large . . . . . . . . . . . . . . . . 61 6.5.12. 414 URI Too Long . . . . . . . . . . . . . . . . . . . 61 6.5.13. 415 Unsupported Media Type . . . . . . . . . . . . . . 61 6.5.14. 417 Expectation Failed . . . . . . . . . . . . . . . . 62 6.5.15. 426 Upgrade Required . . . . . . . . . . . . . . . . . 62 6.6. Server Error 5xx . . . . . . . . . . . . . . . . . . . . . 62 6.6.1. 500 Internal Server Error . . . . . . . . . . . . . . 62 6.6.2. 501 Not Implemented . . . . . . . . . . . . . . . . . 63 6.6.3. 502 Bad Gateway . . . . . . . . . . . . . . . . . . . 63 6.6.4. 503 Service Unavailable . . . . . . . . . . . . . . . 63 6.6.5. 504 Gateway Timeout . . . . . . . . . . . . . . . . . 63 6.6.6. 505 HTTP Version Not Supported . . . . . . . . . . . . 63 7. Response Header Fields . . . . . . . . . . . . . . . . . . . . 64 7.1. Control Data . . . . . . . . . . . . . . . . . . . . . . . 64 7.1.1. Origination Date . . . . . . . . . . . . . . . . . . . 64 7.1.2. Location . . . . . . . . . . . . . . . . . . . . . . . 68 7.1.3. Retry-After . . . . . . . . . . . . . . . . . . . . . 69 7.1.4. Vary . . . . . . . . . . . . . . . . . . . . . . . . . 70 7.2. Validator Header Fields . . . . . . . . . . . . . . . . . 71 7.3. Authentication Challenges . . . . . . . . . . . . . . . . 72 7.4. Response Context . . . . . . . . . . . . . . . . . . . . . 72 7.4.1. Allow . . . . . . . . . . . . . . . . . . . . . . . . 72 7.4.2. Server . . . . . . . . . . . . . . . . . . . . . . . . 73 8. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 73 8.1. Method Registry . . . . . . . . . . . . . . . . . . . . . 74 8.1.1. Procedure . . . . . . . . . . . . . . . . . . . . . . 74 8.1.2. Considerations for New Methods . . . . . . . . . . . . 74 8.1.3. Registrations . . . . . . . . . . . . . . . . . . . . 75 8.2. Status Code Registry . . . . . . . . . . . . . . . . . . . 75 8.2.1. Procedure . . . . . . . . . . . . . . . . . . . . . . 75 8.2.2. Considerations for New Status Codes . . . . . . . . . 76 8.2.3. Registrations . . . . . . . . . . . . . . . . . . . . 76 8.3. Header Field Registry . . . . . . . . . . . . . . . . . . 77 8.3.1. Considerations for New Header Fields . . . . . . . . . 78 8.3.2. Registrations . . . . . . . . . . . . . . . . . . . . 80 8.4. Content Coding Registry . . . . . . . . . . . . . . . . . 80 8.4.1. Procedure . . . . . . . . . . . . . . . . . . . . . . 81 8.4.2. Registrations . . . . . . . . . . . . . . . . . . . . 81 9. Security Considerations . . . . . . . . . . . . . . . . . . . 81 9.1. Attacks Based on File and Path Names . . . . . . . . . . . 82 9.2. Attacks Based on Command, Code, or Query Injection . . . . 82 9.3. Disclosure of Personal Information . . . . . . . . . . . . 83 9.4. Disclosure of Sensitive Information in URIs . . . . . . . 83 9.5. Disclosure of Fragment after Redirects . . . . . . . . . . 83 9.6. Disclosure of Product Information . . . . . . . . . . . . 84 9.7. Browser Fingerprinting . . . . . . . . . . . . . . . . . . 84 10. Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . 85 11. References . . . . . . . . . . . . . . . . . . . . . . . . . . 85 11.1. Normative References . . . . . . . . . . . . . . . . . . . 85 11.2. Informative References . . . . . . . . . . . . . . . . . . 86 Appendix A. Differences between HTTP and MIME . . . . . . . . . . 88 A.1. MIME-Version . . . . . . . . . . . . . . . . . . . . . . . 88 A.2. Conversion to Canonical Form . . . . . . . . . . . . . . . 89 A.3. Conversion of Date Formats . . . . . . . . . . . . . . . . 89 A.4. Conversion of Content-Encoding . . . . . . . . . . . . . . 89 A.5. Conversion of Content-Transfer-Encoding . . . . . . . . . 90 A.6. MHTML and Line-Length Limitations . . . . . . . . . . . . 90 Appendix B. Changes from RFC 2616 . . . . . . . . . . . . . . . . 90 Appendix C. Imported ABNF . . . . . . . . . . . . . . . . . . . . 93 Appendix D. Collected ABNF . . . . . . . . . . . . . . . . . . . 93 Index . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 96 Section 1., paragraph 1: OLD: Each Hypertext Transfer Protocol (HTTP) message is either a request or a response. A server listens on a connection for a request, parses each message received, interprets the message semantics in relation to the identified request target, and responds to that request with one or more response messages. A client constructs request messages to communicate specific intentions, and examines received responses to see if the intentions were carried out and determine how to interpret the results. This document defines HTTP/1.1 request and response semantics in terms of the architecture defined in [RFC7230]. NEW: Each Hypertext Transfer Protocol (HTTP) message is either a request or a response. A server listens on a connection for a request, parses each message received, interprets the message semantics in relation to the identified request target, and responds to that request with one or more response messages. A client constructs request messages to communicate specific intentions, examines received responses to see if the intentions were carried out, and determines how to interpret the results. This document defines HTTP/1.1 request and response semantics in terms of the architecture defined in [RFC7230]. Section 2., paragraph 1: OLD: The target of an HTTP request is called a resource. HTTP does not limit the nature of a resource; it merely defines an interface that might be used to interact with resources. Each resource is identified by a Uniform Resource Identifier (URI), as described in Section 2.7 of [RFC7230]. NEW: The target of an HTTP request is called a "resource". HTTP does not limit the nature of a resource; it merely defines an interface that might be used to interact with resources. Each resource is identified by a Uniform Resource Identifier (URI), as described in Section 2.7 of [RFC7230]. Section 3., paragraph 3: OLD: An origin server might be provided with, or capable of generating, multiple representations that are each intended to reflect the current state of a target resource. In such cases, some algorithm is used by the origin server to select one of those representations as most applicable to a given request, usually based on content negotiation. This "selected representation" is used to provide the data and metadata for evaluating conditional requests [RFC7232] and constructing the payload for 200 (OK) and 304 (Not Modified) responses to GET (Section 4.3.1). NEW: An origin server might be provided with, or be capable of generating, multiple representations that are each intended to reflect the current state of a target resource. In such cases, some algorithm is used by the origin server to select one of those representations as most applicable to a given request, usually based on content negotiation. This "selected representation" is used to provide the data and metadata for evaluating conditional requests [RFC7232] and constructing the payload for 200 (OK) and 304 (Not Modified) responses to GET (Section 4.3.1). Section 3.1.1.1., paragraph 1: OLD: HTTP uses Internet Media Types [RFC2046] in the Content-Type (Section 3.1.1.5) and Accept (Section 5.3.2) header fields in order to provide open and extensible data typing and type negotiation. Media types define both a data format and various processing models: how to process that data in accordance with each context in which it is received. NEW: HTTP uses Internet media types [RFC2046] in the Content-Type (Section 3.1.1.5) and Accept (Section 5.3.2) header fields in order to provide open and extensible data typing and type negotiation. Media types define both a data format and various processing models: how to process that data in accordance with each context in which it is received. Section 3.1.1.1., paragraph 5: OLD: The type, subtype, and parameter name tokens are case-insensitive. Parameter values might or might not be case-sensitive, depending on the semantics of the parameter name. The presence or absence of a parameter might be significant to the processing of a media-type, depending on its definition within the media type registry. NEW: The type, subtype, and parameter name tokens are case insensitive. Parameter values might or might not be case sensitive, depending on the semantics of the parameter name. The presence or absence of a parameter might be significant to the processing of a media-type, depending on its definition within the media type registry. Section 3.1.1.1., paragraph 6: OLD: A parameter value that matches the token production can be transmitted as either a token or within a quoted-string. The quoted and unquoted values are equivalent. For example, the following examples are all equivalent, but the first is preferred for consistency: NEW: A parameter value that matches the token production can be transmitted either as a token or within a quoted-string. The quoted and unquoted values are equivalent. For example, the following examples are all equivalent, but the first is preferred for consistency: Section 3.1.1.2., paragraph 3: OLD: Charset names ought to be registered in IANA Character Set registry () according to the procedures defined in [RFC2978]. NEW: Charset names ought to be registered in the IANA "Character Sets" registry according to the procedures defined in [RFC2978]. Section 3.1.1.3., paragraph 2: OLD: MIME's canonical form requires that media subtypes of the "text" type use CRLF as the text line break. HTTP allows the transfer of text media with plain CR or LF alone representing a line break, when such line breaks are consistent for an entire representation. An HTTP sender MAY generate, and a recipient MUST be able to parse, line breaks in text media that consist of CRLF, bare CR, or bare LF. In addition, text media in HTTP is not limited to charsets that use octets 13 and 10 for CR and LF, respectively. This flexibility regarding line breaks applies only to text within a representation that has been assigned a "text" media type; it does not apply to "multipart" types or HTTP elements outside the payload body (e.g., header fields). NEW: MIME's canonical form requires that media subtypes of the "text" type use CRLF as the text line break. HTTP allows the transfer of text media with plain carriage return (CR) or line feed (LF) alone representing a line break, when such line breaks are consistent for an entire representation. An HTTP sender MAY generate, and a recipient MUST be able to parse, line breaks in text media that consist of CRLF, bare CR, or bare LF. In addition, text media in HTTP is not limited to charsets that use octets 13 and 10 for CR and LF, respectively. This flexibility regarding line breaks applies only to text within a representation that has been assigned a "text" media type; it does not apply to "multipart" types or HTTP elements outside the payload body (e.g., header fields). Section 3.1.2.1., paragraph 3: OLD: All content-coding values are case-insensitive and ought to be registered within the HTTP Content Coding registry, as defined in Section 8.4. They are used in the Accept-Encoding (Section 5.3.4) and Content-Encoding (Section 3.1.2.2) header fields. NEW: All content-coding values are case insensitive and ought to be registered within the "HTTP Content Coding Registry", as defined in Section 8.4. They are used in the Accept-Encoding (Section 5.3.4) and Content-Encoding (Section 3.1.2.2) header fields. Section 3.1.3.1., paragraph 4: OLD: A language tag is a sequence of one or more case-insensitive subtags, each separated by a hyphen character ("-", %x2D). In most cases, a language tag consists of a primary language subtag that identifies a broad family of related languages (e.g., "en" = English) which is optionally followed by a series of subtags that refine or narrow that language's range (e.g., "en-CA" = the variety of English as communicated in Canada). Whitespace is not allowed within a language tag. Example tags include: NEW: A language tag is a sequence of one or more case-insensitive subtags, each separated by a hyphen character ("-", %x2D). In most cases, a language tag consists of a primary language subtag that identifies a broad family of related languages (e.g., "en" = English), which is optionally followed by a series of subtags that refine or narrow that language's range (e.g., "en-CA" = the variety of English as communicated in Canada). Whitespace is not allowed within a language tag. Example tags include: Section 3.1.3.2., paragraph 5: OLD: If no Content-Language is specified, the default is that the content is intended for all language audiences. This might mean that the sender does not consider it to be specific to any natural language, or that the sender does not know for which language it is intended. NEW: If no Content-Language is specified, the default is that the content is intended for all language audiences. This might mean that the sender does not consider it to be specific to any natural language, or that the sender does not know which language is being used. Section 406, paragraph 1: OLD: Reactive negotiation is advantageous when the response would vary over commonly-used dimensions (such as type, language, or encoding), when the origin server is unable to determine a user agent's capabilities from examining the request, and generally when public caches are used to distribute server load and reduce network usage. NEW: Reactive negotiation is advantageous when the response would vary over commonly used dimensions (such as type, language, or encoding), when the origin server is unable to determine a user agent's capabilities from examining the request, and generally when public caches are used to distribute server load and reduce network usage. Section 4.1., paragraph 4: OLD: HTTP was originally designed to be usable as an interface to distributed object systems. The request method was envisioned as applying semantics to a target resource in much the same way as invoking a defined method on an identified object would apply semantics. The method token is case-sensitive because it might be used as a gateway to object-based systems with case-sensitive method names. NEW: HTTP was originally designed to be usable as an interface to distributed object systems. The request method was envisioned as applying semantics to a target resource in much the same way as invoking a defined method on an identified object would apply semantics. The method token is case sensitive because it might be used as a gateway to object-based systems with case-sensitive method names. Section 4.1., paragraph 5: OLD: Unlike distributed objects, the standardized request methods in HTTP are not resource-specific, since uniform interfaces provide for better visibility and reuse in network-based systems [REST]. Once defined, a standardized method ought to have the same semantics when applied to any resource, though each resource determines for itself whether those semantics are implemented or allowed. NEW: Unlike distributed objects, the standardized request methods in HTTP are not resource specific, since uniform interfaces provide for better visibility and reuse in network-based systems [REST]. Once defined, a standardized method ought to have the same semantics when applied to any resource, though each resource determines for itself whether those semantics are implemented or allowed. Section 4.1., paragraph 9: OLD: Additional methods, outside the scope of this specification, have been standardized for use in HTTP. All such methods ought to be registered within the HTTP Method Registry maintained by IANA, as defined in Section 8.1. NEW: Additional methods, outside the scope of this specification, have been standardized for use in HTTP. All such methods ought to be registered within the "Hypertext Transfer Protocol (HTTP) Method" registry maintained by IANA, as defined in Section 8.1. Section 4.2.1., paragraph 2: OLD: This definition of safe methods does not prevent an implementation from including behavior that is potentially harmful, not entirely read-only, or which causes side-effects while invoking a safe method. What is important, however, is that the client did not request that additional behavior and cannot be held accountable for it. For example, most servers append request information to access log files at the completion of every response, regardless of the method, and that is considered safe even though the log storage might become full and crash the server. Likewise, a safe request initiated by selecting an advertisement on the Web will often have the side-effect of charging an advertising account. NEW: This definition of safe method does not prevent an implementation from including behavior that is potentially harmful, that is not entirely read-only, or that causes side effects while invoking a safe method. What is important, however, is that the client did not request that additional behavior and cannot be held accountable for it. For example, most servers append request information to access log files at the completion of every response, regardless of the method, and that is considered safe even though the log storage might become full and crash the server. Likewise, a safe request initiated by selecting an advertisement on the Web will often have the side effect of charging an advertising account. Section 4.2.1., paragraph 6: OLD: When a resource is constructed such that parameters within the effective request URI have the effect of selecting an action, it is the resource owner's responsibility to ensure that the action is consistent with the request method semantics. For example, it is common for Web-based content editing software to use actions within query parameters, such as "page?do=delete". If the purpose of such a resource is to perform an unsafe action, then the resource owner MUST disable or disallow that action when it is accessed using a safe request method. Failure to do so will result in unfortunate side- effects when automated processes perform a GET on every URI reference for the sake of link maintenance, pre-fetching, building a search index, etc. NEW: When a resource is constructed such that parameters within the effective request URI have the effect of selecting an action, it is the resource owner's responsibility to ensure that the action is consistent with the request method semantics. For example, it is common for Web-based content editing software to use actions within query parameters, such as "page?do=delete". If the purpose of such a resource is to perform an unsafe action, then the resource owner MUST disable or disallow that action when it is accessed using a safe request method. Failure to do so will result in unfortunate side effects when automated processes perform a GET on every URI reference for the sake of link maintenance, pre-fetching, building a search index, etc. Section 4.2.2., paragraph 2: OLD: Like the definition of safe, the idempotent property only applies to what has been requested by the user; a server is free to log each request separately, retain a revision control history, or implement other non-idempotent side-effects for each idempotent request. NEW: Like the definition of safe, the idempotent property only applies to what has been requested by the user; a server is free to log each request separately, retain a revision control history, or implement other non-idempotent side effects for each idempotent request. Section 4.2.3., paragraph 1: OLD: Request methods can be defined as "cacheable" to indicate that responses to them are allowed to be stored for future reuse; for specific requirements see [RFC7234]. In general, safe methods that do not depend on a current or authoritative response are defined as cacheable; this specification defines GET, HEAD and POST as cacheable, although the overwhelming majority of cache implementations only support GET and HEAD. NEW: Request methods can be defined as "cacheable" to indicate that responses to them are allowed to be stored for future reuse; for specific requirements see [RFC7234]. In general, safe methods that do not depend on a current or authoritative response are defined as cacheable; this specification defines GET, HEAD, and POST as cacheable, although the overwhelming majority of cache implementations only support GET and HEAD. Section 4.3.1., paragraph 2: OLD: It is tempting to think of resource identifiers as remote file system pathnames, and of representations as being a copy of the contents of such files. In fact, that is how many resources are implemented (see Section 9.1 for related security considerations). However, there are no such limitations in practice. The HTTP interface for a resource is just as likely to be implemented as a tree of content objects, a programmatic view on various database records, or a gateway to other information systems. Even when the URI mapping mechanism is tied to a file system, an origin server might be configured to execute the files with the request as input and send the output as the representation, rather than transfer the files directly. Regardless, only the origin server needs to know how each of its resource identifiers corresponds to an implementation, and how each implementation manages to select and send a current representation of the target resource in a response to GET. NEW: It is tempting to think of resource identifiers as remote file system pathnames and of representations as being a copy of the contents of such files. In fact, that is how many resources are implemented (see Section 9.1 for related security considerations). However, there are no such limitations in practice. The HTTP interface for a resource is just as likely to be implemented as a tree of content objects, a programmatic view on various database records, or a gateway to other information systems. Even when the URI mapping mechanism is tied to a file system, an origin server might be configured to execute the files with the request as input and send the output as the representation rather than transfer the files directly. Regardless, only the origin server needs to know how each of its resource identifiers corresponds to an implementation and how each implementation manages to select and send a current representation of the target resource in a response to GET. Section 4.3.3., paragraph 6: OLD: An origin server indicates response semantics by choosing an appropriate status code depending on the result of processing the POST request; almost all of the status codes defined by this specification might be received in a response to POST (the exceptions being 206, 304, and 416). NEW: An origin server indicates response semantics by choosing an appropriate status code depending on the result of processing the POST request; almost all of the status codes defined by this specification might be received in a response to POST (the exceptions being 206 (Partial Content), 304 (Not Modified), and 416 (Range Not Satisfiable)). Section 4.3.4., paragraph 10: OLD: An origin server MUST NOT send a validator header field (Section 7.2), such as an ETag or Last-Modified field, in a successful response to PUT unless the request's representation data was saved without any transformation applied to the body (i.e., the resource's new representation data is identical to the representation data received in the PUT request) and the validator field value reflects the new representation. This requirement allows a user agent to know when the representation body it has in memory remains current as a result of the PUT, thus not in need of retrieving again from the origin server, and that the new validator(s) received in the response can be used for future conditional requests in order to prevent accidental overwrites (Section 5.2). NEW: An origin server MUST NOT send a validator header field (Section 7.2), such as an ETag or Last-Modified field, in a successful response to PUT unless the request's representation data was saved without any transformation applied to the body (i.e., the resource's new representation data is identical to the representation data received in the PUT request) and the validator field value reflects the new representation. This requirement allows a user agent to know when the representation body it has in memory remains current as a result of the PUT, thus not in need of being retrieved again from the origin server, and that the new validator(s) received in the response can be used for future conditional requests in order to prevent accidental overwrites (Section 5.2). Section 4.3.4., paragraph 13: OLD: A PUT request applied to the target resource can have side-effects on other resources. For example, an article might have a URI for identifying "the current version" (a resource) that is separate from the URIs identifying each particular version (different resources that at one point shared the same state as the current version resource). A successful PUT request on "the current version" URI might therefore create a new version resource in addition to changing the state of the target resource, and might also cause links to be added between the related resources. NEW: A PUT request applied to the target resource can have side effects on other resources. For example, an article might have a URI for identifying "the current version" (a resource) that is separate from the URIs identifying each particular version (different resources that at one point shared the same state as the current version resource). A successful PUT request on "the current version" URI might therefore create a new version resource in addition to changing the state of the target resource, and might also cause links to be added between the related resources. Section 4.3.5., paragraph 1: OLD: The DELETE method requests that the origin server remove the association between the target resource and its current functionality. In effect, this method is similar to the rm command in UNIX: it expresses a deletion operation on the URI mapping of the origin server, rather than an expectation that the previously associated information be deleted. NEW: The DELETE method requests that the origin server remove the association between the target resource and its current functionality. In effect, this method is similar to the rm command in UNIX: it expresses a deletion operation on the URI mapping of the origin server rather than an expectation that the previously associated information be deleted. Section 4.3.6., paragraph 2: OLD: CONNECT is intended only for use in requests to a proxy. An origin server that receives a CONNECT request for itself MAY respond with a 2xx status code to indicate that a connection is established. However, most origin servers do not implement CONNECT. NEW: CONNECT is intended only for use in requests to a proxy. An origin server that receives a CONNECT request for itself MAY respond with a 2xx (Successful) status code to indicate that a connection is established. However, most origin servers do not implement CONNECT. Section 4.3.7., paragraph 1: OLD: The OPTIONS method requests information about the communication options available for the target resource, either at the origin server or an intervening intermediary. This method allows a client to determine the options and/or requirements associated with a resource, or the capabilities of a server, without implying a resource action. NEW: The OPTIONS method requests information about the communication options available for the target resource, at either the origin server or an intervening intermediary. This method allows a client to determine the options and/or requirements associated with a resource, or the capabilities of a server, without implying a resource action. Section 4.3.8., paragraph 2: OLD: A client MUST NOT generate header fields in a TRACE request containing sensitive data that might be disclosed by the response. For example, it would be foolish for a user agent to send stored user credentials [RFC7235] or cookies [RFC6265] in a TRACE request. The final recipient of the request SHOULD exclude any request header fields that are likely to contain sensitive data when that recipient generates the response body. NEW: A client MUST NOT generate header fields in a TRACE request containing sensitive data that might be disclosed by the response. For example, it would be foolish for a user agent to send stored user credentials [RFC7235] or cookies [RFC6265] in a TRACE request. The final recipient of the request SHOULD exclude any request header fields that are likely to contain sensitive data when that recipient generates the response body. Section 5.1.1., paragraph 3: OLD: The Expect field-value is case-insensitive. NEW: The Expect field-value is case insensitive. Section 5.1.1., paragraph 21: OLD: Note: The Expect header field was added after the original publication of HTTP/1.1 [RFC2068] as both the means to request an interim 100 response and the general mechanism for indicating must-understand extensions. However, the extension mechanism has not been used by clients and the must-understand requirements have not been implemented by many servers, rendering the extension mechanism useless. This specification has removed the extension mechanism in order to simplify the definition and processing of 100-continue. NEW: Note: The Expect header field was added after the original publication of HTTP/1.1 [RFC2068] as both the means to request an interim 100 (Continue) response and the general mechanism for indicating must-understand extensions. However, the extension mechanism has not been used by clients and the must-understand requirements have not been implemented by many servers, rendering the extension mechanism useless. This specification has removed the extension mechanism in order to simplify the definition and processing of 100-continue. Section 5.1.2., paragraph 4: OLD: Each intermediary that receives a TRACE or OPTIONS request containing a Max-Forwards header field MUST check and update its value prior to forwarding the request. If the received value is zero (0), the intermediary MUST NOT forward the request; instead, the intermediary MUST respond as the final recipient. If the received Max-Forwards value is greater than zero, the intermediary MUST generate an updated Max-Forwards field in the forwarded message with a field-value that is the lesser of: a) the received value decremented by one (1), or b) the recipient's maximum supported value for Max-Forwards. NEW: Each intermediary that receives a TRACE or OPTIONS request containing a Max-Forwards header field MUST check and update its value prior to forwarding the request. If the received value is zero (0), the intermediary MUST NOT forward the request; instead, the intermediary MUST respond as the final recipient. If the received Max-Forwards value is greater than zero, the intermediary MUST generate an updated Max-Forwards field in the forwarded message with a field-value that is the lesser of a) the received value decremented by one (1) or b) the recipient's maximum supported value for Max-Forwards. Section 5.3.2., paragraph 9: OLD: is interpreted as "I prefer audio/basic, but send me any audio type if it is the best available after an 80% mark-down in quality". NEW: is interpreted as "I prefer audio/basic, but send me any audio type if it is the best available after an 80% markdown in quality". Section 5.3.5., paragraph 6: OLD: A request without any Accept-Language header field implies that the user agent will accept any language in response. If the header field is present in a request and none of the available representations for the response have a matching language tag, the origin server can either disregard the header field by treating the response as if it is not subject to content negotiation, or honor the header field by sending a 406 (Not Acceptable) response. However, the latter is not encouraged, as doing so can prevent users from accessing content that they might be able to use (with translation software, for example). NEW: A request without any Accept-Language header field implies that the user agent will accept any language in response. If the header field is present in a request and none of the available representations for the response have a matching language tag, the origin server can either disregard the header field by treating the response as if it is not subject to content negotiation or honor the header field by sending a 406 (Not Acceptable) response. However, the latter is not encouraged, as doing so can prevent users from accessing content that they might be able to use (with translation software, for example). Section 5.3.5., paragraph 10: OLD: Since intelligibility is highly dependent on the individual user, user agents need to allow user control over the linguistic preference (either through configuration of the user agent itself, or by defaulting to a user controllable system setting). A user agent that does not provide such control to the user MUST NOT send an Accept- Language header field. NEW: Since intelligibility is highly dependent on the individual user, user agents need to allow user control over the linguistic preference (either through configuration of the user agent itself or by defaulting to a user controllable system setting). A user agent that does not provide such control to the user MUST NOT send an Accept- Language header field. Section 5.5.1., paragraph 1: OLD: The "From" header field contains an Internet email address for a human user who controls the requesting user agent. The address ought to be machine-usable, as defined by "mailbox" in Section 3.4 of [RFC5322]: NEW: The "From" header field contains an Internet email address for a human user who controls the requesting user agent. The address ought to be machine usable, as defined by "mailbox" in Section 3.4 of [RFC5322]: Section 5.5.2., paragraph 6: OLD: If the target URI was obtained from a source that does not have its own URI (e.g., input from the user keyboard, or an entry within the user's bookmarks/favorites), the user agent MUST either exclude Referer or send it with a value of "about:blank". NEW: If the target URI was obtained from a source that does not have its own URI (e.g., input from the user keyboard, or an entry within the user's bookmarks/favorites), the user agent MUST either exclude the Referer or send it with a value of "about:blank". Section 5.5.2., paragraph 8: OLD: Some intermediaries have been known to indiscriminately remove Referer header fields from outgoing requests. This has the unfortunate side-effect of interfering with protection against CSRF attacks, which can be far more harmful to their users. Intermediaries and user agent extensions that wish to limit information disclosure in Referer ought to restrict their changes to specific edits, such as replacing internal domain names with pseudonyms or truncating the query and/or path components. An intermediary SHOULD NOT modify or delete the Referer header field when the field value shares the same scheme and host as the request target. NEW: Some intermediaries have been known to indiscriminately remove Referer header fields from outgoing requests. This has the unfortunate side effect of interfering with protection against CSRF attacks, which can be far more harmful to their users. Intermediaries and user agent extensions that wish to limit information disclosure in Referer ought to restrict their changes to specific edits, such as replacing internal domain names with pseudonyms or truncating the query and/or path components. An intermediary SHOULD NOT modify or delete the Referer header field when the field value shares the same scheme and host as the request target. Section 5.5.3., paragraph 1: OLD: The "User-Agent" header field contains information about the user agent originating the request, which is often used by servers to help identify the scope of reported interoperability problems, to work around or tailor responses to avoid particular user agent limitations, and for analytics regarding browser or operating system use. A user agent SHOULD send a User-Agent field in each request unless specifically configured not to do so. NEW: The "User-Agent" header field contains information about the user agent originating the request, which is often used by servers to help identify the scope of reported interoperability problems, to work around or tailor responses to avoid particular user-agent limitations, and for analytics regarding browser or operating system use. A user agent SHOULD send a User-Agent field in each request unless specifically configured not to do so. Section 5.5.3., paragraph 3: OLD: The User-Agent field-value consists of one or more product identifiers, each followed by zero or more comments (Section 3.2 of [RFC7230]), which together identify the user agent software and its significant subproducts. By convention, the product identifiers are listed in decreasing order of their significance for identifying the user agent software. Each product identifier consists of a name and optional version. NEW: The User-Agent field-value consists of one or more product identifiers, each followed by zero or more comments (Section 3.2 of [RFC7230]), which together identify the user-agent software and its significant subproducts. By convention, the product identifiers are listed in decreasing order of their significance for identifying the user-agent software. Each product identifier consists of a name and optional version. Section 5.5.3., paragraph 5: OLD: A sender SHOULD limit generated product identifiers to what is necessary to identify the product; a sender MUST NOT generate advertising or other non-essential information within the product identifier. A sender SHOULD NOT generate information in product- version that is not a version identifier (i.e., successive versions of the same product name ought to only differ in the product-version portion of the product identifier). NEW: A sender SHOULD limit generated product identifiers to what is necessary to identify the product; a sender MUST NOT generate advertising or other nonessential information within the product identifier. A sender SHOULD NOT generate information in product- version that is not a version identifier (i.e., successive versions of the same product name ought only to differ in the product-version portion of the product identifier). Section 5.5.3., paragraph 9: OLD: Likewise, implementations are encouraged not to use the product tokens of other implementations in order to declare compatibility with them, as this circumvents the purpose of the field. If a user agent masquerades as a different user agent, recipients can assume that the user intentionally desires to see responses tailored for that identified user agent, even if they might not work as well for the actual user agent being used. NEW: Likewise, implementations are encouraged not to use the product tokens of other implementations in order to declare compatibility with them, as this circumvents the purpose of the field. If a user agent masquerades as a different user agent, recipients can assume that the user intentionally desires to see responses tailored for that identified user agent, even if they might not work as well for the actual user agent being implemented. Section 6., paragraph 1: OLD: The status-code element is a 3-digit integer code giving the result of the attempt to understand and satisfy the request. NEW: The status-code element is a three-digit integer code giving the result of the attempt to understand and satisfy the request. Section 6., paragraph 3: OLD: For example, if an unrecognized status code of 471 is received by a client, the client can assume that there was something wrong with its request and treat the response as if it had received a 400 status code. The response message will usually contain a representation that explains the status. NEW: For example, if an unrecognized status code of 471 is received by a client, the client can assume that there was something wrong with its request and treat the response as if it had received a 400 (Bad Request) status code. The response message will usually contain a representation that explains the status. Section 6., paragraph 4: OLD: The first digit of the status-code defines the class of response. The last two digits do not have any categorization role. There are 5 values for the first digit: NEW: The first digit of the status-code defines the class of response. The last two digits do not have any categorization role. There are five values for the first digit: Section 6.1., paragraph 2: OLD: Responses with status codes that are defined as cacheable by default (e.g., 200, 203, 204, 206, 300, 301, 404, 405, 410, 414, 501 in this specification) can be reused by a cache with heuristic expiration unless otherwise indicated by the method definition or explicit cache controls [RFC7234]; all other status codes are not cacheable by default. NEW: Responses with status codes that are defined as cacheable by default (e.g., 200, 203, 204, 206, 300, 301, 404, 405, 410, 414, and 501 in this specification) can be reused by a cache with heuristic expiration unless otherwise indicated by the method definition or explicit cache controls [RFC7234]; all other status codes are not cacheable by default. Section 6.1., paragraph 3: OLD: +------+-------------------------------+--------------------------+ | code | reason-phrase | Defined in... | +------+-------------------------------+--------------------------+ | 100 | Continue | Section 6.2.1 | | 101 | Switching Protocols | Section 6.2.2 | | 200 | OK | Section 6.3.1 | | 201 | Created | Section 6.3.2 | | 202 | Accepted | Section 6.3.3 | | 203 | Non-Authoritative Information | Section 6.3.4 | | 204 | No Content | Section 6.3.5 | | 205 | Reset Content | Section 6.3.6 | | 206 | Partial Content | Section 4.1 of [RFC7233] | | 300 | Multiple Choices | Section 6.4.1 | | 301 | Moved Permanently | Section 6.4.2 | | 302 | Found | Section 6.4.3 | | 303 | See Other | Section 6.4.4 | | 304 | Not Modified | Section 4.1 of [RFC7232] | | 305 | Use Proxy | Section 6.4.5 | | 307 | Temporary Redirect | Section 6.4.7 | | 400 | Bad Request | Section 6.5.1 | | 401 | Unauthorized | Section 3.1 of [RFC7235] | | 402 | Payment Required | Section 6.5.2 | | 403 | Forbidden | Section 6.5.3 | | 404 | Not Found | Section 6.5.4 | | 405 | Method Not Allowed | Section 6.5.5 | | 406 | Not Acceptable | Section 6.5.6 | | 407 | Proxy Authentication Required | Section 3.2 of [RFC7235] | | 408 | Request Time-out | Section 6.5.7 | | 409 | Conflict | Section 6.5.8 | | 410 | Gone | Section 6.5.9 | | 411 | Length Required | Section 6.5.10 | | 412 | Precondition Failed | Section 4.2 of [RFC7232] | | 413 | Payload Too Large | Section 6.5.11 | | 414 | URI Too Long | Section 6.5.12 | | 415 | Unsupported Media Type | Section 6.5.13 | | 416 | Range Not Satisfiable | Section 4.4 of [RFC7233] | | 417 | Expectation Failed | Section 6.5.14 | | 426 | Upgrade Required | Section 6.5.15 | | 500 | Internal Server Error | Section 6.6.1 | | 501 | Not Implemented | Section 6.6.2 | | 502 | Bad Gateway | Section 6.6.3 | | 503 | Service Unavailable | Section 6.6.4 | | 504 | Gateway Time-out | Section 6.6.5 | | 505 | HTTP Version Not Supported | Section 6.6.6 | +------+-------------------------------+--------------------------+ NEW: +------+-------------------------------+--------------------------+ | Code | Reason-Phrase | Defined in... | +------+-------------------------------+--------------------------+ | 100 | Continue | Section 6.2.1 | | 101 | Switching Protocols | Section 6.2.2 | | 200 | OK | Section 6.3.1 | | 201 | Created | Section 6.3.2 | | 202 | Accepted | Section 6.3.3 | | 203 | Non-Authoritative Information | Section 6.3.4 | | 204 | No Content | Section 6.3.5 | | 205 | Reset Content | Section 6.3.6 | | 206 | Partial Content | Section 4.1 of [RFC7233] | | 300 | Multiple Choices | Section 6.4.1 | | 301 | Moved Permanently | Section 6.4.2 | | 302 | Found | Section 6.4.3 | | 303 | See Other | Section 6.4.4 | | 304 | Not Modified | Section 4.1 of [RFC7232] | | 305 | Use Proxy | Section 6.4.5 | | 307 | Temporary Redirect | Section 6.4.7 | | 400 | Bad Request | Section 6.5.1 | | 401 | Unauthorized | Section 3.1 of [RFC7235] | | 402 | Payment Required | Section 6.5.2 | | 403 | Forbidden | Section 6.5.3 | | 404 | Not Found | Section 6.5.4 | | 405 | Method Not Allowed | Section 6.5.5 | | 406 | Not Acceptable | Section 6.5.6 | | 407 | Proxy Authentication Required | Section 3.2 of [RFC7235] | | 408 | Request Time-out | Section 6.5.7 | | 409 | Conflict | Section 6.5.8 | | 410 | Gone | Section 6.5.9 | | 411 | Length Required | Section 6.5.10 | | 412 | Precondition Failed | Section 4.2 of [RFC7232] | | 413 | Payload Too Large | Section 6.5.11 | | 414 | URI Too Long | Section 6.5.12 | | 415 | Unsupported Media Type | Section 6.5.13 | | 416 | Range Not Satisfiable | Section 4.4 of [RFC7233] | | 417 | Expectation Failed | Section 6.5.14 | | 426 | Upgrade Required | Section 6.5.15 | | 500 | Internal Server Error | Section 6.6.1 | | 501 | Not Implemented | Section 6.6.2 | | 502 | Bad Gateway | Section 6.6.3 | | 503 | Service Unavailable | Section 6.6.4 | | 504 | Gateway Time-out | Section 6.6.5 | | 505 | HTTP Version Not Supported | Section 6.6.6 | +------+-------------------------------+--------------------------+ Section 6.2., paragraph 1: OLD: The 1xx (Informational) class of status code indicates an interim response for communicating connection status or request progress prior to completing the requested action and sending a final response. All 1xx responses consist of only the status-line and optional header fields, and thus are terminated by the empty line at the end of the header section. Since HTTP/1.0 did not define any 1xx status codes, a server MUST NOT send a 1xx response to an HTTP/1.0 client. NEW: The 1xx (Informational) class of status code indicates an interim response for communicating connection status or request progress prior to completing the requested action and sending a final response. All 1xx responses consist of only the status-line and optional header fields and, thus, are terminated by the empty line at the end of the header section. Since HTTP/1.0 did not define any 1xx status codes, a server MUST NOT send a 1xx response to an HTTP/1.0 client. Section 6.3.3., paragraph 2: OLD: The 202 response is intentionally non-committal. Its purpose is to allow a server to accept a request for some other process (perhaps a batch-oriented process that is only run once per day) without requiring that the user agent's connection to the server persist until the process is completed. The representation sent with this response ought to describe the request's current status and point to (or embed) a status monitor that can provide the user with an estimate of when the request will be fulfilled. NEW: The 202 response is intentionally noncommittal. Its purpose is to allow a server to accept a request for some other process (perhaps a batch-oriented process that is only run once per day) without requiring that the user agent's connection to the server persist until the process is completed. The representation sent with this response ought to describe the request's current status and point to (or embed) a status monitor that can provide the user with an estimate of when the request will be fulfilled. Section 6.4.1., paragraph 5: OLD: Note: The original proposal for 300 defined the URI header field as providing a list of alternative representations, such that it would be usable for 200, 300, and 406 responses and be transferred in responses to the HEAD method. However, lack of deployment and disagreement over syntax led to both URI and Alternates (a subsequent proposal) being dropped from this specification. It is possible to communicate the list using a set of Link header fields [RFC5988], each with a relationship of "alternate", though deployment is a chicken-and-egg problem. NEW: Note: The original proposal for the 300 response defined the URI header field as providing a list of alternative representations, such that it would be usable for 200, 300, and 406 responses and be transferred in responses to the HEAD method. However, lack of deployment and disagreement over syntax led to both URI and Alternates (a subsequent proposal) being dropped from this specification. It is possible to communicate the list using a set of Link header fields [RFC5988], each with a relationship of "alternate", though deployment is a chicken-and-egg problem. Section 6.4.2., paragraph 1: OLD: The 301 (Moved Permanently) status code indicates that the target resource has been assigned a new permanent URI and any future references to this resource ought to use one of the enclosed URIs. Clients with link editing capabilities ought to automatically re-link references to the effective request URI to one or more of the new references sent by the server, where possible. NEW: The 301 (Moved Permanently) status code indicates that the target resource has been assigned a new permanent URI and any future references to this resource ought to use one of the enclosed URIs. Clients with link-editing capabilities ought to automatically re-link references to the effective request URI to one or more of the new references sent by the server, where possible. Section 6.4.4., paragraph 2: OLD: This status code is applicable to any HTTP method. It is primarily used to allow the output of a POST action to redirect the user agent to a selected resource, since doing so provides the information corresponding to the POST response in a form that can be separately identified, bookmarked, and cached independent of the original request. NEW: This status code is applicable to any HTTP method. It is primarily used to allow the output of a POST action to redirect the user agent to a selected resource, since doing so provides the information corresponding to the POST response in a form that can be separately identified, bookmarked, and cached, independent of the original request. Section 6.4.7., paragraph 3: OLD: Note: This status code is similar to 302 (Found), except that it does not allow changing the request method from POST to GET. This specification defines no equivalent counterpart for 301 (Moved Permanently) ([status-308], however, defines the status code 308 (Permanent Redirect) for this purpose). NEW: Note: This status code is similar to 302 (Found), except that it does not allow changing the request method from POST to GET. This specification defines no equivalent counterpart for 301 (Moved Permanently) ([RFC7238]; however, it defines the status code 308 (Permanent Redirect) for this purpose). Section 6.5.1., paragraph 1: OLD: The 400 (Bad Request) status code indicates that the server cannot or will not process the request due to something which is perceived to be a client error (e.g., malformed request syntax, invalid request message framing, or deceptive request routing). NEW: The 400 (Bad Request) status code indicates that the server cannot or will not process the request due to something that is perceived to be a client error (e.g., malformed request syntax, invalid request message framing, or deceptive request routing). Section 5.3, paragraph 0: OLD: The 414 (URI Too Long) status code indicates that the server is refusing to service the request because the request-target (Section 5.3 of [RFC7230]) is longer than the server is willing to interpret. This rare condition is only likely to occur when a client has improperly converted a POST request to a GET request with long query information, when the client has descended into a "black hole" of redirection (e.g., a redirected URI prefix that points to a suffix of itself), or when the server is under attack by a client attempting to exploit potential security holes. NEW: The 414 (URI Too Long) status code indicates that the server is refusing to service the request because the request-target (Section 5.3 of [RFC7230]) is longer than the server is willing to interpret. This rare condition is only likely to occur when a client has improperly converted a POST request to a GET request with long query information, when the client has descended into a "black hole" of redirection (e.g., a redirected URI prefix that points to a suffix of itself) or when the server is under attack by a client attempting to exploit potential security holes. Section 7.1.1.1., paragraph 11: OLD: day-name = %x4D.6F.6E ; "Mon", case-sensitive / %x54.75.65 ; "Tue", case-sensitive / %x57.65.64 ; "Wed", case-sensitive / %x54.68.75 ; "Thu", case-sensitive / %x46.72.69 ; "Fri", case-sensitive / %x53.61.74 ; "Sat", case-sensitive / %x53.75.6E ; "Sun", case-sensitive NEW: day-name = %x4D.6F.6E ; "Mon", case sensitive / %x54.75.65 ; "Tue", case sensitive / %x57.65.64 ; "Wed", case sensitive / %x54.68.75 ; "Thu", case sensitive / %x46.72.69 ; "Fri", case sensitive / %x53.61.74 ; "Sat", case sensitive / %x53.75.6E ; "Sun", case sensitive Section 7.1.1.1., paragraph 13: OLD: day = 2DIGIT month = %x4A.61.6E ; "Jan", case-sensitive / %x46.65.62 ; "Feb", case-sensitive / %x4D.61.72 ; "Mar", case-sensitive / %x41.70.72 ; "Apr", case-sensitive / %x4D.61.79 ; "May", case-sensitive / %x4A.75.6E ; "Jun", case-sensitive / %x4A.75.6C ; "Jul", case-sensitive / %x41.75.67 ; "Aug", case-sensitive / %x53.65.70 ; "Sep", case-sensitive / %x4F.63.74 ; "Oct", case-sensitive / %x4E.6F.76 ; "Nov", case-sensitive / %x44.65.63 ; "Dec", case-sensitive year = 4DIGIT NEW: day = 2DIGIT month = %x4A.61.6E ; "Jan", case sensitive / %x46.65.62 ; "Feb", case sensitive / %x4D.61.72 ; "Mar", case sensitive / %x41.70.72 ; "Apr", case sensitive / %x4D.61.79 ; "May", case sensitive / %x4A.75.6E ; "Jun", case sensitive / %x4A.75.6C ; "Jul", case sensitive / %x41.75.67 ; "Aug", case sensitive / %x53.65.70 ; "Sep", case sensitive / %x4F.63.74 ; "Oct", case sensitive / %x4E.6F.76 ; "Nov", case sensitive / %x44.65.63 ; "Dec", case sensitive year = 4DIGIT Section 7.1.1.1., paragraph 14: OLD: GMT = %x47.4D.54 ; "GMT", case-sensitive NEW: GMT = %x47.4D.54 ; "GMT", case sensitive Section 7.1.1.1., paragraph 19: OLD: day-name-l = %x4D.6F.6E.64.61.79 ; "Monday", case-sensitive / %x54.75.65.73.64.61.79 ; "Tuesday", case-sensitive / %x57.65.64.6E.65.73.64.61.79 ; "Wednesday", case-sensitive / %x54.68.75.72.73.64.61.79 ; "Thursday", case-sensitive / %x46.72.69.64.61.79 ; "Friday", case-sensitive / %x53.61.74.75.72.64.61.79 ; "Saturday", case-sensitive / %x53.75.6E.64.61.79 ; "Sunday", case-sensitive NEW: day-name-l = %x4D.6F.6E.64.61.79 ; "Monday", case sensitive / %x54.75.65.73.64.61.79 ; "Tuesday", case sensitive / %x57.65.64.6E.65.73.64.61.79 ; "Wednesday", case sensitive / %x54.68.75.72.73.64.61.79 ; "Thursday", case sensitive / %x46.72.69.64.61.79 ; "Friday", case sensitive / %x53.61.74.75.72.64.61.79 ; "Saturday", case sensitive / %x53.75.6E.64.61.79 ; "Sunday", case sensitive Section 7.1.2., paragraph 5: OLD: If the Location value provided in a 3xx (Redirection) does not have a fragment component, a user agent MUST process the redirection as if the value inherits the fragment component of the URI reference used to generate the request target (i.e., the redirection inherits the original reference's fragment, if any). NEW: If the Location value provided in a 3xx (Redirection) response does not have a fragment component, a user agent MUST process the redirection as if the value inherits the fragment component of the URI reference used to generate the request target (i.e., the redirection inherits the original reference's fragment, if any). Section 7.1.4., paragraph 1: OLD: The "Vary" header field in a response describes what parts of a request message, aside from the method, Host header field, and request target, might influence the origin server's process for selecting and representing this response. The value consists of either a single asterisk ("*") or a list of header field names (case- insensitive). NEW: The "Vary" header field in a response describes what parts of a request message, aside from the method, Host header field, and request target, might influence the origin server's process for selecting and representing this response. The value consists of either a single asterisk ("*") or a list of header field names (case insensitive). Section 1., paragraph 1: OLD: 2. To inform user agent recipients that this response is subject to content negotiation (Section 5.3) and that a different representation might be sent in a subsequent request if additional parameters are provided in the listed header fields (proactive negotiation). NEW: 2. To inform user-agent recipients that this response is subject to content negotiation (Section 5.3) and that a different representation might be sent in a subsequent request if additional parameters are provided in the listed header fields (proactive negotiation). Section 7.2., paragraph 3: OLD: For example, an ETag header field in a 201 response communicates the entity-tag of the newly created resource's representation, so that it can be used in later conditional requests to prevent the "lost update" problem [RFC7232]. NEW: For example, an ETag header field in a 201 (Created) response communicates the entity-tag of the newly created resource's representation, so that it can be used in later conditional requests to prevent the "lost update" problem [RFC7232]. Section 8.1., paragraph 1: OLD: The HTTP Method Registry defines the name space for the request method token (Section 4). The method registry will be created and maintained at (the suggested URI) . NEW: The "Hypertext Transfer Protocol (HTTP) Method Registry" defines the namespace for the request method token (Section 4). The "HTTP Method Registry" has been created and is now maintained at . Section 8.1.2., paragraph 3: OLD: A new method definition needs to indicate whether it is safe (Section 4.2.1), idempotent (Section 4.2.2), cacheable (Section 4.2.3), what semantics are to be associated with the payload body if any is present in the request, and what refinements the method makes to header field or status code semantics. If the new method is cacheable, its definition ought to describe how, and under what conditions, a cache can store a response and use it to satisfy a subsequent request. The new method ought to describe whether it can be made conditional (Section 5.2) and, if so, how a server responds when the condition is false. Likewise, if the new method might have some use for partial response semantics ([RFC7233]), it ought to document this too. NEW: A new method definition needs to indicate whether it is safe (Section 4.2.1), idempotent (Section 4.2.2), or cacheable (Section 4.2.3). It needs to indicate what semantics are to be associated with the payload body if any is present in the request and what refinements the method makes to header field or status code semantics. If the new method is cacheable, its definition ought to describe how, and under what conditions, a cache can store a response and use it to satisfy a subsequent request. The new method ought to describe whether it can be made conditional (Section 5.2) and, if so, how a server responds when the condition is false. Likewise, if the new method might have some use for partial response semantics ([RFC7233]), it ought to document this, too. Section 8.1.3., paragraph 1: OLD: The HTTP Method Registry shall be populated with the registrations below: NEW: The "Hypertext Transfer Protocol (HTTP) Method Registry" has been populated with the registrations below: Section 8.2., paragraph 1: OLD: The HTTP Status Code Registry defines the name space for the response status-code token (Section 6). The status code registry is maintained at . NEW: The "Hypertext Transfer Protocol (HTTP) Status Code Registry" defines the namespace for the response status-code token (Section 6). The "HTTP Status Codes" registry is maintained at . Section 8.2., paragraph 2: OLD: This Section replaces the registration procedure for HTTP Status Codes previously defined in Section 7.1 of [RFC2817]. NEW: This section replaces the registration procedure for HTTP Status Codes previously defined in Section 7.1 of [RFC2817]. Section 8.2.3., paragraph 1: OLD: The HTTP Status Code Registry shall be updated with the registrations below: NEW: The "HTTP Status Codes" registry has been updated with the registrations below: Section 8.3., paragraph 1: OLD: HTTP header fields are registered within the Message Header Field Registry located at , as defined by [BCP90]. NEW: HTTP header fields are registered within the "Message Headers" registry located at as defined by [BCP90]. Section 8.3.1., paragraph 3: OLD: Authors of specifications defining new fields are advised to keep the name as short as practical and to not prefix the name with "X-" unless the header field will never be used on the Internet. (The "x-" prefix idiom has been extensively misused in practice; it was intended to only be used as a mechanism for avoiding name collisions inside proprietary software or intranet processing, since the prefix would ensure that private names never collide with a newly registered Internet name; see [BCP178] for further information) NEW: Authors of specifications defining new fields are advised to keep the name as short as practical and not to prefix the name with "X-" unless the header field will never be used on the Internet. (The "X-" prefix idiom has been extensively misused in practice; it was intended to only be used as a mechanism for avoiding name collisions inside proprietary software or intranet processing, since the prefix would ensure that private names never collide with a newly registered Internet name; see [BCP178] for further information). Section 8.3.1., paragraph 4: OLD: New header field values typically have their syntax defined using ABNF ([RFC5234]), using the extension defined in Section 7 of [RFC7230] as necessary, and are usually constrained to the range of ASCII characters. Header fields needing a greater range of characters can use an encoding such as the one defined in [RFC5987]. NEW: New header field values typically have their syntax defined using ABNF ([RFC5234]) (implementing the extension defined in Section 7 of [RFC7230] as necessary), and they are usually constrained to the range of ASCII characters. Header fields needing a greater range of characters can use an encoding such as the one defined in [RFC5987]. Section 8.3.1., paragraph 13: OLD: o Whether the field is a single value, or whether it can be a list (delimited by commas; see Section 3.2 of [RFC7230]). NEW: o Whether the field is a single value or whether it can be a list (delimited by commas; see Section 3.2 of [RFC7230]). Section 8.3.2., paragraph 1: OLD: The Message Header Field Registry shall be updated with the following permanent registrations: NEW: The "Message Headers" registry has been updated with the following permanent registrations: Section 8.3.2., paragraph 2: OLD: +-------------------+----------+----------+-----------------+ | Header Field Name | Protocol | Status | Reference | +-------------------+----------+----------+-----------------+ | Accept | http | standard | Section 5.3.2 | | Accept-Charset | http | standard | Section 5.3.3 | | Accept-Encoding | http | standard | Section 5.3.4 | | Accept-Language | http | standard | Section 5.3.5 | | Allow | http | standard | Section 7.4.1 | | Content-Encoding | http | standard | Section 3.1.2.2 | | Content-Language | http | standard | Section 3.1.3.2 | | Content-Location | http | standard | Section 3.1.4.2 | | Content-Type | http | standard | Section 3.1.1.5 | | Date | http | standard | Section 7.1.1.2 | | Expect | http | standard | Section 5.1.1 | | From | http | standard | Section 5.5.1 | | Location | http | standard | Section 7.1.2 | | MIME-Version | http | standard | Appendix A.1 | | Max-Forwards | http | standard | Section 5.1.2 | | Referer | http | standard | Section 5.5.2 | | Retry-After | http | standard | Section 7.1.3 | | Server | http | standard | Section 7.4.2 | | User-Agent | http | standard | Section 5.5.3 | | Vary | http | standard | Section 7.1.4 | +-------------------+----------+----------+-----------------+ NEW: +-------------------+----------+----------+-----------------+ | Header Field Name | Protocol | Status | Reference | +-------------------+----------+----------+-----------------+ | Accept | http | standard | Section 5.3.2 | | Accept-Charset | http | standard | Section 5.3.3 | | Accept-Encoding | http | standard | Section 5.3.4 | | Accept-Language | http | standard | Section 5.3.5 | | Allow | http | standard | Section 7.4.1 | | Content-Encoding | http | standard | Section 3.1.2.2 | | Content-Language | http | standard | Section 3.1.3.2 | | Content-Location | http | standard | Section 3.1.4.2 | | Content-Type | http | standard | Section 3.1.1.5 | | Date | http | standard | Section 7.1.1.2 | | Expect | http | standard | Section 5.1.1 | | From | http | standard | Section 5.5.1 | | Location | http | standard | Section 7.1.2 | | Max-Forwards | http | standard | Section 5.1.2 | | MIME-Version | http | standard | Appendix A.1 | | Referer | http | standard | Section 5.5.2 | | Retry-After | http | standard | Section 7.1.3 | | Server | http | standard | Section 7.4.2 | | User-Agent | http | standard | Section 5.5.3 | | Vary | http | standard | Section 7.1.4 | +-------------------+----------+----------+-----------------+ Section 8.4., paragraph 1: OLD: The HTTP Content Coding Registry defines the name space for content coding names (Section 4.2 of [RFC7230]). The content coding registry is maintained at . NEW: The "HTTP Content Coding Registry" defines the namespace for content coding names (Section 4.2 of [RFC7230]). The "HTTP Content Coding Registry" is maintained at . Section 8.4.1., paragraph 1: OLD: Content Coding registrations MUST include the following fields: NEW: Content coding registrations MUST include the following fields: Section 8.4.1., paragraph 6: OLD: Values to be added to this name space require IETF Review (see Section 4.1 of [RFC5226]), and MUST conform to the purpose of content coding defined in this section. NEW: Values to be added to this namespace require IETF Review (see Section 4.1 of [RFC5226]) and MUST conform to the purpose of content coding defined in this section. Section 8.4.2., paragraph 1: OLD: The HTTP Content Codings Registry shall be updated with the registrations below: NEW: The "HTTP Content Codings Registry" has been updated with the registrations below: Section 9., paragraph 2: OLD: The list of considerations below is not exhaustive. Most security concerns related to HTTP semantics are about securing server-side applications (code behind the HTTP interface), securing user agent processing of payloads received via HTTP, or secure use of the Internet in general, rather than security of the protocol. Various organizations maintain topical information and links to current research on Web application security (e.g., [OWASP]). NEW: The list of considerations below is not exhaustive. Most security concerns related to HTTP semantics are about securing server-side applications (code behind the HTTP interface) or securing user-agent processing of payloads received via HTTP. Secure use of the Internet in general, rather than security of the protocol, might also be related. Various organizations maintain topical information and links to current research on Web application security (e.g., [OWASP]). Section 9., paragraph 3: OLD: 9.1. Attacks Based On File and Path Names NEW: 9.1. Attacks Based on File and Path Names Section 9., paragraph 4: OLD: Origin servers frequently make use of their local file system to manage the mapping from effective request URI to resource representations. Implementers need to be aware that most file systems are not designed to protect against malicious file or path names, and thus depend on the origin server to avoid mapping to file names, folders, or directories that have special significance to the system. NEW: Origin servers frequently make use of their local file system to manage the mapping from effective request URI to resource representations. Implementers need to be aware that most file systems are not designed to protect against malicious file or path names and, thus, depend on the origin server to avoid mapping to file names, folders, or directories that have special significance to the system. Section 9., paragraph 5: OLD: For example, UNIX, Microsoft Windows, and other operating systems use ".." as a path component to indicate a directory level above the current one, and use specially named paths or file names to send data to system devices. Similar naming conventions might exist within other types of storage systems. Likewise, local storage systems have an annoying tendency to prefer user-friendliness over security when handling invalid or unexpected characters, recomposition of decomposed characters, and case-normalization of case-insensitive names. NEW: For example, UNIX, Microsoft Windows, and other operating systems use ".." as a path component to indicate a directory level above the current one, and they use specially named paths or file names to send data to system devices. Similar naming conventions might exist within other types of storage systems. Likewise, local storage systems have an annoying tendency to prefer user-friendliness over security when handling invalid or unexpected characters, recomposition of decomposed characters, and case-normalization of case-insensitive names. Section 9., paragraph 7: OLD: 9.2. Attacks Based On Command, Code, or Query Injection NEW: 9.2. Attacks Based on Command, Code, or Query Injection Section 9.4., paragraph 3: OLD: Since the Referer header field tells a target site about the context that resulted in a request, it has the potential to reveal information about the user's immediate browsing history and any personal information that might be found in the referring resource's URI. Limitations on Referer are described in Section 5.5.2 to address some of its security considerations. NEW: Since the Referer header field tells a target site about the context that resulted in a request, it has the potential to reveal information about the user's immediate browsing history and any personal information that might be found in the referring resource's URI. Limitations on the Referer header field are described in Section 5.5.2 to address some of its security considerations. Section 11.1., paragraph 1: OLD: [RFC2045] Freed, N. and N. Borenstein, "Multipurpose Internet Mail Extensions (MIME) Part One: Format of Internet Message Bodies", RFC 2045, November 1996. NEW: [RFC2045] Freed, N. and N. Borenstein, "Multipurpose Internet Mail Extensions (MIME) Part One: Format of Internet Message Bodies", RFC 2045, November 1996. Section 11.1., paragraph 2: OLD: [RFC2046] Freed, N. and N. Borenstein, "Multipurpose Internet Mail Extensions (MIME) Part Two: Media Types", RFC 2046, November 1996. NEW: [RFC2046] Freed, N. and N. Borenstein, "Multipurpose Internet Mail Extensions (MIME) Part Two: Media Types", RFC 2046, November 1996. Section 11.1., paragraph 4: OLD: [RFC3986] Berners-Lee, T., Fielding, R., and L. Masinter, "Uniform Resource Identifier (URI): Generic Syntax", STD 66, RFC 3986, January 2005. NEW: [RFC3986] Berners-Lee, T., Fielding, R., and L. Masinter, "Uniform Resource Identifier (URI): Generic Syntax", STD 66, RFC 3986, January 2005. Section 11.1., paragraph 5: OLD: [RFC4647] Phillips, A., Ed. and M. Davis, Ed., "Matching of Language Tags", BCP 47, RFC 4647, September 2006. NEW: [RFC4647] Phillips, A., Ed. and M. Davis, Ed., "Matching of Language Tags", BCP 47, RFC 4647, September 2006. Section 11.1., paragraph 6: OLD: [RFC5234] Crocker, D., Ed. and P. Overell, "Augmented BNF for Syntax Specifications: ABNF", STD 68, RFC 5234, January 2008. NEW: [RFC5234] Crocker, D., Ed. and P. Overell, "Augmented BNF for Syntax Specifications: ABNF", STD 68, RFC 5234, January 2008. Section 11.1., paragraph 7: OLD: [RFC5646] Phillips, A., Ed. and M. Davis, Ed., "Tags for Identifying Languages", BCP 47, RFC 5646, September 2009. NEW: [RFC5646] Phillips, A., Ed. and M. Davis, Ed., "Tags for Identifying Languages", BCP 47, RFC 5646, September 2009. Section 11.1., paragraph 9: OLD: [RFC7230] Fielding, R., Ed. and J. Reschke, Ed., "Hypertext Transfer Protocol (HTTP/1.1): Message Syntax and Routing", draft-ietf-httpbis-p1-messaging-latest (work in progress), May 2014. NEW: [RFC7230] Fielding, R., Ed. and J. Reschke, Ed., "Hypertext Transfer Protocol (HTTP/1.1): Message Syntax and Routing", RFC 7230, May 2014. Section 11.1., paragraph 10: OLD: [RFC7232] Fielding, R., Ed. and J. Reschke, Ed., "Hypertext Transfer Protocol (HTTP/1.1): Conditional Requests", draft-ietf-httpbis-p4-conditional-latest (work in progress), May 2014. NEW: [RFC7232] Fielding, R., Ed. and J. Reschke, Ed., "Hypertext Transfer Protocol (HTTP/1.1): Conditional Requests", RFC 7232, May 2014. Section 11.1., paragraph 11: OLD: [RFC7233] Fielding, R., Ed., Lafon, Y., Ed., and J. Reschke, Ed., "Hypertext Transfer Protocol (HTTP/1.1): Range Requests", draft-ietf-httpbis-p5-range-latest (work in progress), May 2014. NEW: [RFC7233] Fielding, R., Ed., Lafon, Y., Ed., and J. Reschke, Ed., "Hypertext Transfer Protocol (HTTP/1.1): Range Requests", RFC 7233, May 2014. Section 11.1., paragraph 12: OLD: [RFC7234] Fielding, R., Ed., Nottingham, M., Ed., and J. Reschke, Ed., "Hypertext Transfer Protocol (HTTP/1.1): Caching", draft-ietf-httpbis-p6-cache-latest (work in progress), May 2014. NEW: [RFC7234] Fielding, R., Ed., Nottingham, M., Ed., and J. Reschke, Ed., "Hypertext Transfer Protocol (HTTP/1.1): Caching", RFC 7234, May 2014. Section 11.1., paragraph 13: OLD: [RFC7235] Fielding, R., Ed. and J. Reschke, Ed., "Hypertext Transfer Protocol (HTTP/1.1): Authentication", draft-ietf-httpbis-p7-auth-latest (work in progress), May 2014. NEW: [RFC7235] Fielding, R., Ed. and J. Reschke, Ed., "Hypertext Transfer Protocol (HTTP/1.1): Authentication", RFC 7235, May 2014. Section 11.2., paragraph 3: OLD: [BCP90] Klyne, G., Nottingham, M., and J. Mogul, "Registration Procedures for Message Header Fields", BCP 90, RFC 3864, September 2004. NEW: [BCP90] Klyne, G., Nottingham, M., and J. Mogul, "Registration Procedures for Message Header Fields", BCP 90, RFC 3864, September 2004. Section 11.2., paragraph 4: OLD: [OWASP] van der Stock, A., Ed., "A Guide to Building Secure Web Applications and Web Services", The Open Web Application Security Project (OWASP) 2.0.1, July 2005, . NEW: [OWASP] van der Stock, A., Ed., "A Guide to Building Secure Web Applications and Web Services", The Open Web Application Security Project (OWASP) 2.0.1, July 2005, . Section 11.2., paragraph 5: OLD: [REST] Fielding, R., "Architectural Styles and the Design of Network-based Software Architectures", Doctoral Dissertation, University of California, Irvine, September 2000, . NEW: [REST] Fielding, R., "Architectural Styles and the Design of Network-based Software Architectures", Doctoral Dissertation, University of California, Irvine, September 2000, . Section 11.2., paragraph 6: OLD: [RFC1945] Berners-Lee, T., Fielding, R., and H. Nielsen, "Hypertext Transfer Protocol -- HTTP/1.0", RFC 1945, May 1996. NEW: [RFC1945] Berners-Lee, T., Fielding, R., and H. Nielsen, "Hypertext Transfer Protocol -- HTTP/1.0", RFC 1945, May 1996. Section 11.2., paragraph 7: OLD: [RFC2049] Freed, N. and N. Borenstein, "Multipurpose Internet Mail Extensions (MIME) Part Five: Conformance Criteria and Examples", RFC 2049, November 1996. NEW: [RFC2049] Freed, N. and N. Borenstein, "Multipurpose Internet Mail Extensions (MIME) Part Five: Conformance Criteria and Examples", RFC 2049, November 1996. Section 11.2., paragraph 8: OLD: [RFC2068] Fielding, R., Gettys, J., Mogul, J., Nielsen, H., and T. Berners-Lee, "Hypertext Transfer Protocol -- HTTP/1.1", RFC 2068, January 1997. NEW: [RFC2068] Fielding, R., Gettys, J., Mogul, J., Nielsen, H., and T. Berners-Lee, "Hypertext Transfer Protocol -- HTTP/1.1", RFC 2068, January 1997. Section 11.2., paragraph 9: OLD: [RFC2295] Holtman, K. and A. Mutz, "Transparent Content Negotiation in HTTP", RFC 2295, March 1998. NEW: [RFC2295] Holtman, K. and A. Mutz, "Transparent Content Negotiation in HTTP", RFC 2295, March 1998. Section 11.2., paragraph 11: OLD: [RFC2557] Palme, F., Hopmann, A., Shelness, N., and E. Stefferud, "MIME Encapsulation of Aggregate Documents, such as HTML (MHTML)", RFC 2557, March 1999. NEW: [RFC2557] Palme, F., Hopmann, A., Shelness, N., and E. Stefferud, "MIME Encapsulation of Aggregate Documents, such as HTML (MHTML)", RFC 2557, March 1999. Section 11.2., paragraph 16: OLD: [RFC5226] Narten, T. and H. Alvestrand, "Guidelines for Writing an IANA Considerations Section in RFCs", BCP 26, RFC 5226, May 2008. NEW: [RFC5226] Narten, T. and H. Alvestrand, "Guidelines for Writing an IANA Considerations Section in RFCs", BCP 26, RFC 5226, May 2008. Section 11.2., paragraph 17: OLD: [RFC5246] Dierks, T. and E. Rescorla, "The Transport Layer Security (TLS) Protocol Version 1.2", RFC 5246, August 2008. NEW: [RFC5246] Dierks, T. and E. Rescorla, "The Transport Layer Security (TLS) Protocol Version 1.2", RFC 5246, August 2008. Section 11.2., paragraph 20: OLD: [RFC5905] Mills, D., Martin, J., Ed., Burbank, J., and W. Kasch, "Network Time Protocol Version 4: Protocol and Algorithms Specification", RFC 5905, June 2010. NEW: [RFC5905] Mills, D., Martin, J., Ed., Burbank, J., and W. Kasch, "Network Time Protocol Version 4: Protocol and Algorithms Specification", RFC 5905, June 2010. Section 11.2., paragraph 24: OLD: [RFC6266] Reschke, J., "Use of the Content-Disposition Header Field in the Hypertext Transfer Protocol (HTTP)", RFC 6266, June 2011. NEW: [RFC6266] Reschke, J., "Use of the Content-Disposition Header Field in the Hypertext Transfer Protocol (HTTP)", RFC 6266, June 2011. Section 11.2., paragraph 25: OLD: [status-308] Reschke, J., "The Hypertext Transfer Protocol (HTTP) Status Code 308 (Permanent Redirect)", draft-reschke-http-status-308-07 (work in progress), March 2012. NEW: [RFC7238] Reschke, J., "The Hypertext Transfer Protocol (HTTP) Status Code 308 (Permanent Redirect)", RFC 7238, May 2014. Appendix A., paragraph 1: OLD: HTTP/1.1 uses many of the constructs defined for the Internet Message Format [RFC5322] and the Multipurpose Internet Mail Extensions (MIME) [RFC2045] to allow a message body to be transmitted in an open variety of representations and with extensible header fields. However, RFC 2045 is focused only on email; applications of HTTP have many characteristics that differ from email, and hence HTTP has features that differ from MIME. These differences were carefully chosen to optimize performance over binary connections, to allow greater freedom in the use of new media types, to make date comparisons easier, and to acknowledge the practice of some early HTTP servers and clients. NEW: HTTP/1.1 uses many of the constructs defined for the Internet Message Format [RFC5322] and the Multipurpose Internet Mail Extensions (MIME) [RFC2045] to allow a message body to be transmitted in an open variety of representations and with extensible header fields. However, RFC 2045 is focused only on email; applications of HTTP have many characteristics that differ from email; hence, HTTP has features that differ from MIME. These differences were carefully chosen to optimize performance over binary connections, to allow greater freedom in the use of new media types, to make date comparisons easier, and to acknowledge the practice of some early HTTP servers and clients. Appendix A., paragraph 16: OLD: A.6. MHTML and Line Length Limitations NEW: A.6. MHTML and Line-Length Limitations Appendix A., paragraph 17: OLD: HTTP implementations that share code with MHTML [RFC2557] implementations need to be aware of MIME line length limitations. Since HTTP does not have this limitation, HTTP does not fold long lines. MHTML messages being transported by HTTP follow all conventions of MHTML, including line length limitations and folding, canonicalization, etc., since HTTP transfers message-bodies as payload and, aside from the "multipart/byteranges" type (Appendix A of [RFC7233]), does not interpret the content or any MIME header lines that might be contained therein. NEW: HTTP implementations that share code with MHTML [RFC2557] implementations need to be aware of MIME line-length limitations. Since HTTP does not have this limitation, HTTP does not fold long lines. MHTML messages being transported by HTTP follow all conventions of MHTML, including line-length limitations and folding, canonicalization, etc., since HTTP transfers message-bodies as payload and, aside from the "multipart/byteranges" type (Appendix A of [RFC7233]), does not interpret the content or any MIME header lines that might be contained therein. Appendix B., paragraph 2: OLD: A new requirement has been added that semantics embedded in a URI should be disabled when those semantics are inconsistent with the request method, since this is a common cause of interoperability failure. (Section 2) NEW: A new requirement has been added that semantics embedded in a URI be disabled when those semantics are inconsistent with the request method, since this is a common cause of interoperability failure (Section 2). Appendix B., paragraph 3: OLD: An algorithm has been added for determining if a payload is associated with a specific identifier. (Section 3.1.4.1) NEW: An algorithm has been added for determining if a payload is associated with a specific identifier (Section 3.1.4.1). Appendix B., paragraph 4: OLD: The default charset of ISO-8859-1 for text media types has been removed; the default is now whatever the media type definition says. Likewise, special treatment of ISO-8859-1 has been removed from the Accept-Charset header field. (Section 3.1.1.3 and Section 5.3.3) NEW: The default charset of ISO-8859-1 for text media types has been removed; the default is now whatever the media type definition says. Likewise, special treatment of ISO-8859-1 has been removed from the Accept-Charset header field. (Sections 3.1.1.3 and 5.3.3.) Appendix B., paragraph 5: OLD: The definition of Content-Location has been changed to no longer affect the base URI for resolving relative URI references, due to poor implementation support and the undesirable effect of potentially breaking relative links in content-negotiated resources. (Section 3.1.4.2) NEW: The definition of Content-Location has been changed to no longer affect the base URI for resolving relative URI references, due to poor implementation support and the undesirable effect of potentially breaking relative links in content-negotiated resources (Section 3.1.4.2). Appendix B., paragraph 6: OLD: To be consistent with the method-neutral parsing algorithm of [RFC7230], the definition of GET has been relaxed so that requests can have a body, even though a body has no meaning for GET. (Section 4.3.1) NEW: To be consistent with the method-neutral parsing algorithm of [RFC7230], the definition of GET has been relaxed so that requests can have a body, even though a body has no meaning for GET (Section 4.3.1). Appendix B., paragraph 7: OLD: Servers are no longer required to handle all Content-* header fields and use of Content-Range has been explicitly banned in PUT requests. (Section 4.3.4) NEW: Servers are no longer required to handle all Content-* header fields and use of Content-Range has been explicitly banned in PUT requests (Section 4.3.4). Appendix B., paragraph 8: OLD: Definition of the CONNECT method has been moved from [RFC2817] to this specification. (Section 4.3.6) NEW: Definition of the CONNECT method has been moved from [RFC2817] to this specification (Section 4.3.6). Appendix B., paragraph 9: OLD: The OPTIONS and TRACE request methods have been defined as being safe. (Section 4.3.7 and Section 4.3.8) NEW: The OPTIONS and TRACE request methods have been defined as being safe (Section 4.3.7 and Section 4.3.8). Appendix B., paragraph 10: OLD: The Expect header field's extension mechanism has been removed due to widely-deployed broken implementations. (Section 5.1.1) NEW: The Expect header field's extension mechanism has been removed due to widely deployed broken implementations (Section 5.1.1). Appendix B., paragraph 11: OLD: The Max-Forwards header field has been restricted to the OPTIONS and TRACE methods; previously, extension methods could have used it as well. (Section 5.1.2) NEW: The Max-Forwards header field has been restricted to the OPTIONS and TRACE methods; previously, extension methods could have used it as well (Section 5.1.2). Appendix B., paragraph 12: OLD: The "about:blank" URI has been suggested as a value for the Referer header field when no referring URI is applicable, which distinguishes that case from others where the Referer field is not sent or has been removed. (Section 5.5.2) NEW: The "about:blank" URI has been suggested as a value for the Referer header field when no referring URI is applicable, which distinguishes that case from others where the Referer field is not sent or has been removed (Section 5.5.2). Appendix B., paragraph 13: OLD: The following status codes are now cacheable (that is, they can be stored and reused by a cache without explicit freshness information present): 204, 404, 405, 414, 501. (Section 6) NEW: The following status codes are now cacheable (that is, they can be stored and reused by a cache without explicit freshness information present): 204, 404, 405, 414, 501 (Section 6). Appendix B., paragraph 14: OLD: The 201 (Created) status description has been changed to allow for the possibility that more than one resource has been created. (Section 6.3.2) NEW: The 201 (Created) status description has been changed to allow for the possibility that more than one resource has been created (Section 6.3.2). Appendix B., paragraph 15: OLD: The definition of 203 (Non-Authoritative Information) has been broadened to include cases of payload transformations as well. (Section 6.3.4) NEW: The definition of 203 (Non-Authoritative Information) has been broadened to include cases of payload transformations as well (Section 6.3.4). Appendix B., paragraph 16: OLD: The set of request methods that are safe to automatically redirect is no longer closed; user agents are able to make that determination based upon the request method semantics. The redirect status codes 301, 302, and 307 no longer have normative requirements on response payloads and user interaction. (Section 6.4) NEW: The set of request methods that are safe to automatically redirect is no longer closed; user agents are able to make that determination based upon the request method semantics. The redirect status codes 301, 302, and 307 no longer have normative requirements on response payloads and user interaction (Section 6.4). Appendix B., paragraph 17: OLD: The status codes 301 and 302 have been changed to allow user agents to rewrite the method from POST to GET. (Sections 6.4.2 and 6.4.3) NEW: The status codes 301 and 302 have been changed to allow user agents to rewrite the method from POST to GET. (Sections 6.4.2 and 6.4.3.) Appendix B., paragraph 18: OLD: The description of 303 (See Other) status code has been changed to allow it to be cached if explicit freshness information is given, and a specific definition has been added for a 303 response to GET. (Section 6.4.4) NEW: The description of the 303 (See Other) status code has been changed to allow it to be cached if explicit freshness information is given, and a specific definition has been added for a 303 response to GET (Section 6.4.4). Appendix B., paragraph 19: OLD: The 305 (Use Proxy) status code has been deprecated due to security concerns regarding in-band configuration of a proxy. (Section 6.4.5) NEW: The 305 (Use Proxy) status code has been deprecated due to security concerns regarding in-band configuration of a proxy (Section 6.4.5). Appendix B., paragraph 20: OLD: The 400 (Bad Request) status code has been relaxed so that it isn't limited to syntax errors. (Section 6.5.1) NEW: The 400 (Bad Request) status code has been relaxed so that it isn't limited to syntax errors (Section 6.5.1). Appendix B., paragraph 21: OLD: The 426 (Upgrade Required) status code has been incorporated from [RFC2817]. (Section 6.5.15) NEW: The 426 (Upgrade Required) status code has been incorporated from [RFC2817] (Section 6.5.15). Appendix B., paragraph 22: OLD: The target of requirements on HTTP-date and the Date header field have been reduced to those systems generating the date, rather than all systems sending a date. (Section 7.1.1) NEW: The target of requirements on HTTP-date and the Date header field have been reduced to those systems generating the date, rather than all systems sending a date (Section 7.1.1). Appendix B., paragraph 23: OLD: The syntax of the Location header field has been changed to allow all URI references, including relative references and fragments, along with some clarifications as to when use of fragments would not be appropriate. (Section 7.1.2) NEW: The syntax of the Location header field has been changed to allow all URI references, including relative references and fragments, along with some clarifications as to when use of fragments would not be appropriate (Section 7.1.2). Appendix B., paragraph 24: OLD: Allow has been reclassified as a response header field, removing the option to specify it in a PUT request. Requirements relating to the content of Allow have been relaxed; correspondingly, clients are not required to always trust its value. (Section 7.4.1) NEW: Allow has been reclassified as a response header field, removing the option to specify it in a PUT request. Requirements relating to the content of Allow have been relaxed; correspondingly, clients are not required to always trust its value (Section 7.4.1). A Method Registry has been defined (Section 8.1). Appendix B., paragraph 25: OLD: A Method Registry has been defined. (Section 8.1) The Status Code Registry has been redefined by this specification; previously, it was defined in Section 7.1 of [RFC2817]. (Section 8.2) NEW: The Status Code Registry has been redefined by this specification; previously, it was defined in Section 7.1 of [RFC2817] (Section 8.2). Appendix B., paragraph 26: OLD: Registration of Content Codings has been changed to require IETF Review. (Section 8.4) NEW: Registration of content codings has been changed to require IETF Review (Section 8.4). Section 1.2, paragraph 1: OLD: Accept = [ ( "," / ( media-range [ accept-params ] ) ) *( OWS "," [ OWS ( media-range [ accept-params ] ) ] ) ] Accept-Charset = *( "," OWS ) ( ( charset / "*" ) [ weight ] ) *( OWS "," [ OWS ( ( charset / "*" ) [ weight ] ) ] ) Accept-Encoding = [ ( "," / ( codings [ weight ] ) ) *( OWS "," [ OWS ( codings [ weight ] ) ] ) ] Accept-Language = *( "," OWS ) ( language-range [ weight ] ) *( OWS "," [ OWS ( language-range [ weight ] ) ] ) Allow = [ ( "," / method ) *( OWS "," [ OWS method ] ) ] NEW: Accept = [ ( "," / ( media-range [ accept-params ] ) ) *( OWS "," [ OWS ( media-range [ accept-params ] ) ] ) ] Accept-Charset = *( "," OWS ) ( ( charset / "*" ) [ weight ] ) *( OWS "," [ OWS ( ( charset / "*" ) [ weight ] ) ] ) Accept-Encoding = [ ( "," / ( codings [ weight ] ) ) *( OWS "," [ OWS ( codings [ weight ] ) ] ) ] Accept-Language = *( "," OWS ) ( language-range [ weight ] ) *( OWS "," [ OWS ( language-range [ weight ] ) ] ) Allow = [ ( "," / method ) *( OWS "," [ OWS method ] ) ] Section 1.2, paragraph 3: OLD: Content-Encoding = *( "," OWS ) content-coding *( OWS "," [ OWS content-coding ] ) Content-Language = *( "," OWS ) language-tag *( OWS "," [ OWS language-tag ] ) Content-Location = absolute-URI / partial-URI Content-Type = media-type Date = HTTP-date NEW: Content-Encoding = *( "," OWS ) content-coding *( OWS "," [ OWS content-coding ] ) Content-Language = *( "," OWS ) language-tag *( OWS "," [ OWS language-tag ] ) Content-Location = absolute-URI / partial-URI Content-Type = media-type Date = HTTP-date Section 1.2, paragraph 24: OLD: parameter = token "=" ( token / quoted-string ) partial-URI = product = token [ "/" product-version ] product-version = token quoted-string = qvalue = ( "0" [ "." *3DIGIT ] ) / ( "1" [ "." *3"0" ] ) NEW: parameter = token "=" ( token / quoted-string ) partial-URI = product = token [ "/" product-version ] product-version = token quoted-string = qvalue = ( "0" [ "." *3DIGIT ] ) / ( "1" [ "." *3"0" ] ) Section 1.2, paragraph 30: OLD: Appendix E. Change Log (to be removed by RFC Editor before publication) E.1. Since RFC 2616 Changes up to the IETF Last Call draft are summarized in . E.2. Since draft-ietf-httpbis-p2-semantics-24 Closed issues: o : "Review Cachability of Status Codes WRT 'Negative Caching'" o : "RFC 1305 ref needs to be updated to 5905" o : "idempotency: clarify 'effect'" o : "APPSDIR review of draft-ietf-httpbis-p2-semantics-24" o : "move IANA registrations to correct draft" E.3. Since draft-ietf-httpbis-p2-semantics-25 Closed issues: o : "Gen-Art review of draft-ietf-httpbis-p2-semantics-24 with security considerations" o : "IESG ballot on draft-ietf-httpbis-p2-semantics-25" o : "add 'stateless' to Abstract" o : "improve introduction of list rule" o : "requirement on implementing methods according to their semantics" o : "considerations for new headers: privacy" o : "augment security considerations with pointers to current research" E.4. Since draft-ietf-httpbis-p2-semantics-26 None yet. Index NEW: Index Section 1.2, paragraph 50: OLD: M Max-Forwards header field 36 MIME-Version header field 89 NEW: M Max-Forwards header field 36 MIME-Version header field 88