Ignore:
Timestamp:
05/01/13 11:42:34 (10 years ago)
Author:
fielding@…
Message:

(editorial) Clarify that GET means retrieval; addresses #315

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1 edited

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  • draft-ietf-httpbis/latest/p6-cache.html

    r2082 r2088  
    452452  }
    453453  @bottom-center {
    454        content: "Expires July 8, 2013";
     454       content: "Expires July 9, 2013";
    455455  }
    456456  @bottom-right {
     
    498498      <meta name="dct.creator" content="Reschke, J. F.">
    499499      <meta name="dct.identifier" content="urn:ietf:id:draft-ietf-httpbis-p6-cache-latest">
    500       <meta name="dct.issued" scheme="ISO8601" content="2013-01-04">
     500      <meta name="dct.issued" scheme="ISO8601" content="2013-01-05">
    501501      <meta name="dct.replaces" content="urn:ietf:rfc:2616">
    502502      <meta name="dct.abstract" content="The Hypertext Transfer Protocol (HTTP) is an application-level protocol for distributed, collaborative, hypertext information systems. This document defines requirements on HTTP caches and the associated header fields that control cache behavior or indicate cacheable response messages.">
     
    524524            </tr>
    525525            <tr>
    526                <td class="left">Expires: July 8, 2013</td>
     526               <td class="left">Expires: July 9, 2013</td>
    527527               <td class="right">J. Reschke, Editor</td>
    528528            </tr>
     
    533533            <tr>
    534534               <td class="left"></td>
    535                <td class="right">January 4, 2013</td>
     535               <td class="right">January 5, 2013</td>
    536536            </tr>
    537537         </tbody>
     
    559559         in progress”.
    560560      </p>
    561       <p>This Internet-Draft will expire on July 8, 2013.</p>
     561      <p>This Internet-Draft will expire on July 9, 2013.</p>
    562562      <h1><a id="rfc.copyrightnotice" href="#rfc.copyrightnotice">Copyright Notice</a></h1>
    563563      <p>Copyright © 2013 IETF Trust and the persons identified as the document authors. All rights reserved.</p>
     
    795795      </p>
    796796      <p id="rfc.section.2.p.2">Each <dfn>cache entry</dfn> consists of a cache key and one or more HTTP responses corresponding to prior requests that used the same key. The most common
    797          form of cache entry is a successful result of a retrieval request: i.e., a <a href="p2-semantics.html#status.200" class="smpl">200 (OK)</a> response containing a representation of the resource identified by the request target. However, it is also possible to cache
    798          negative results (e.g., <a href="p2-semantics.html#status.404" class="smpl">404 (Not
    799             Found)</a>, incomplete results (e.g., <a href="p5-range.html#status.206" class="smpl">206 (Partial
    800             Content)</a>), and responses to methods other than GET if the method's definition allows such caching and defines something suitable for
     797         form of cache entry is a successful result of a retrieval request: i.e., a <a href="p2-semantics.html#status.200" class="smpl">200 (OK)</a> response to a GET request, which contains a representation of the resource identified by the request target (<a href="p2-semantics.html#GET" title="GET">Section 4.3.1</a> of <a href="#Part2" id="rfc.xref.Part2.2"><cite title="Hypertext Transfer Protocol (HTTP/1.1): Semantics and Content">[Part2]</cite></a>). However, it is also possible to cache negative results (e.g., <a href="p2-semantics.html#status.404" class="smpl">404 (Not Found)</a>), incomplete results (e.g., <a href="p5-range.html#status.206" class="smpl">206 (Partial Content)</a>), and responses to methods other than GET if the method's definition allows such caching and defines something suitable for
    801798         use as a cache key.
    802799      </p>
     
    886883      <p id="rfc.section.4.p.3">When a stored response is used to satisfy a request without validation, a cache <em class="bcp14">MUST</em> send a single <a href="#header.age" class="smpl">Age</a> header field (<a href="#header.age" id="rfc.xref.header.age.1" title="Age">Section&nbsp;7.1</a>) in the response with a value equal to the stored response's current_age; see <a href="#age.calculations" title="Calculating Age">Section&nbsp;4.1.3</a>.
    887884      </p>
    888       <p id="rfc.section.4.p.4">A cache <em class="bcp14">MUST</em> write through requests with methods that are unsafe (<a href="p2-semantics.html#safe.methods" title="Safe Methods">Section 4.2.1</a> of <a href="#Part2" id="rfc.xref.Part2.2"><cite title="Hypertext Transfer Protocol (HTTP/1.1): Semantics and Content">[Part2]</cite></a>) to the origin server; i.e., a cache is not allowed to generate a reply to such a request before having forwarded the request
     885      <p id="rfc.section.4.p.4">A cache <em class="bcp14">MUST</em> write through requests with methods that are unsafe (<a href="p2-semantics.html#safe.methods" title="Safe Methods">Section 4.2.1</a> of <a href="#Part2" id="rfc.xref.Part2.3"><cite title="Hypertext Transfer Protocol (HTTP/1.1): Semantics and Content">[Part2]</cite></a>) to the origin server; i.e., a cache is not allowed to generate a reply to such a request before having forwarded the request
    889886         and having received a corresponding response.
    890887      </p>
     
    940937      <h3 id="rfc.section.4.1.2"><a href="#rfc.section.4.1.2">4.1.2</a>&nbsp;<a id="heuristic.freshness" href="#heuristic.freshness">Calculating Heuristic Freshness</a></h3>
    941938      <p id="rfc.section.4.1.2.p.1">If no explicit expiration time is present in a stored response that has a status code whose definition allows heuristic freshness
    942          to be used (including the following in <a href="p2-semantics.html#status.codes" title="Response Status Codes">Section 6</a> of <a href="#Part2" id="rfc.xref.Part2.3"><cite title="Hypertext Transfer Protocol (HTTP/1.1): Semantics and Content">[Part2]</cite></a>: <a href="p2-semantics.html#status.200" class="smpl">200 (OK)</a>, <a href="p2-semantics.html#status.203" class="smpl">203 (Non-Authoritative Information)</a>, <a href="p5-range.html#status.206" class="smpl">206 (Partial
     939         to be used (including the following in <a href="p2-semantics.html#status.codes" title="Response Status Codes">Section 6</a> of <a href="#Part2" id="rfc.xref.Part2.4"><cite title="Hypertext Transfer Protocol (HTTP/1.1): Semantics and Content">[Part2]</cite></a>: <a href="p2-semantics.html#status.200" class="smpl">200 (OK)</a>, <a href="p2-semantics.html#status.203" class="smpl">203 (Non-Authoritative Information)</a>, <a href="p5-range.html#status.206" class="smpl">206 (Partial
    943940            Content)</a>, <a href="p2-semantics.html#status.300" class="smpl">300 (Multiple Choices)</a>, <a href="p2-semantics.html#status.301" class="smpl">301 (Moved
    944941            Permanently)</a> and <a href="p2-semantics.html#status.410" class="smpl">410 (Gone)</a>), a cache <em class="bcp14">MAY</em> calculate a heuristic expiration time. A cache <em class="bcp14">MUST NOT</em> use heuristics to determine freshness for responses with status codes that do not explicitly allow it.
     
    972969      </p>
    973970      <ul class="empty">
    974          <li>The term "date_value" denotes the value of the Date header field, in a form appropriate for arithmetic operations. See <a href="p2-semantics.html#header.date" title="Date">Section 7.1.1.2</a> of <a href="#Part2" id="rfc.xref.Part2.4"><cite title="Hypertext Transfer Protocol (HTTP/1.1): Semantics and Content">[Part2]</cite></a> for the definition of the Date header field, and for requirements regarding responses without it.
     971         <li>The term "date_value" denotes the value of the Date header field, in a form appropriate for arithmetic operations. See <a href="p2-semantics.html#header.date" title="Date">Section 7.1.1.2</a> of <a href="#Part2" id="rfc.xref.Part2.5"><cite title="Hypertext Transfer Protocol (HTTP/1.1): Semantics and Content">[Part2]</cite></a> for the definition of the Date header field, and for requirements regarding responses without it.
    975972         </li>
    976973      </ul>
     
    10921089      </ul>
    10931090      <h2 id="rfc.section.4.3"><a href="#rfc.section.4.3">4.3</a>&nbsp;<a id="caching.negotiated.responses" href="#caching.negotiated.responses">Using Negotiated Responses</a></h2>
    1094       <p id="rfc.section.4.3.p.1">When a cache receives a request that can be satisfied by a stored response that has a <a href="p2-semantics.html#header.vary" class="smpl">Vary</a> header field (<a href="p2-semantics.html#header.vary" title="Vary">Section 7.2.1</a> of <a href="#Part2" id="rfc.xref.Part2.5"><cite title="Hypertext Transfer Protocol (HTTP/1.1): Semantics and Content">[Part2]</cite></a>), it <em class="bcp14">MUST NOT</em> use that response unless all of the selecting header fields nominated by the Vary header field match in both the original
     1091      <p id="rfc.section.4.3.p.1">When a cache receives a request that can be satisfied by a stored response that has a <a href="p2-semantics.html#header.vary" class="smpl">Vary</a> header field (<a href="p2-semantics.html#header.vary" title="Vary">Section 7.2.1</a> of <a href="#Part2" id="rfc.xref.Part2.6"><cite title="Hypertext Transfer Protocol (HTTP/1.1): Semantics and Content">[Part2]</cite></a>), it <em class="bcp14">MUST NOT</em> use that response unless all of the selecting header fields nominated by the Vary header field match in both the original
    10951092         request (i.e., that associated with the stored response), and the presented request.
    10961093      </p>
     
    11511148      </ul>
    11521149      <h1 id="rfc.section.6"><a href="#rfc.section.6">6.</a>&nbsp;<a id="invalidation.after.updates.or.deletions" href="#invalidation.after.updates.or.deletions">Request Methods that Invalidate</a></h1>
    1153       <p id="rfc.section.6.p.1">Because unsafe request methods (<a href="p2-semantics.html#safe.methods" title="Safe Methods">Section 4.2.1</a> of <a href="#Part2" id="rfc.xref.Part2.6"><cite title="Hypertext Transfer Protocol (HTTP/1.1): Semantics and Content">[Part2]</cite></a>) such as PUT, POST or DELETE have the potential for changing state on the origin server, intervening caches can use them
     1150      <p id="rfc.section.6.p.1">Because unsafe request methods (<a href="p2-semantics.html#safe.methods" title="Safe Methods">Section 4.2.1</a> of <a href="#Part2" id="rfc.xref.Part2.7"><cite title="Hypertext Transfer Protocol (HTTP/1.1): Semantics and Content">[Part2]</cite></a>) such as PUT, POST or DELETE have the potential for changing state on the origin server, intervening caches can use them
    11541151         to keep their contents up-to-date.
    11551152      </p>
     
    14191416         that time.
    14201417      </p>
    1421       <p id="rfc.section.7.3.p.3">The Expires value is an HTTP-date timestamp, as defined in <a href="p2-semantics.html#http.date" title="Date/Time Formats">Section 7.1.1.1</a> of <a href="#Part2" id="rfc.xref.Part2.7"><cite title="Hypertext Transfer Protocol (HTTP/1.1): Semantics and Content">[Part2]</cite></a>.
     1418      <p id="rfc.section.7.3.p.3">The Expires value is an HTTP-date timestamp, as defined in <a href="p2-semantics.html#http.date" title="Date/Time Formats">Section 7.1.1.1</a> of <a href="#Part2" id="rfc.xref.Part2.8"><cite title="Hypertext Transfer Protocol (HTTP/1.1): Semantics and Content">[Part2]</cite></a>.
    14221419      </p>
    14231420      <div id="rfc.figure.u.9"></div><pre class="inline"><span id="rfc.iref.g.5"></span>  <a href="#header.expires" class="smpl">Expires</a> = <a href="#imported.abnf" class="smpl">HTTP-date</a>
     
    17761773      <h1 id="rfc.section.10"><a href="#rfc.section.10">10.</a>&nbsp;<a id="security.considerations" href="#security.considerations">Security Considerations</a></h1>
    17771774      <p id="rfc.section.10.p.1">This section is meant to inform developers, information providers, and users of known security concerns specific to HTTP/1.1
    1778          caching. More general security considerations are addressed in HTTP messaging <a href="#Part1" id="rfc.xref.Part1.11"><cite title="Hypertext Transfer Protocol (HTTP/1.1): Message Syntax and Routing">[Part1]</cite></a> and semantics <a href="#Part2" id="rfc.xref.Part2.8"><cite title="Hypertext Transfer Protocol (HTTP/1.1): Semantics and Content">[Part2]</cite></a>.
     1775         caching. More general security considerations are addressed in HTTP messaging <a href="#Part1" id="rfc.xref.Part1.11"><cite title="Hypertext Transfer Protocol (HTTP/1.1): Message Syntax and Routing">[Part1]</cite></a> and semantics <a href="#Part2" id="rfc.xref.Part2.9"><cite title="Hypertext Transfer Protocol (HTTP/1.1): Semantics and Content">[Part2]</cite></a>.
    17791776      </p>
    17801777      <p id="rfc.section.10.p.2">Caches expose additional potential vulnerabilities, since the contents of the cache represent an attractive target for malicious
     
    19521949  <a href="#imported.abnf" class="smpl">uri-host</a>      = &lt;uri-host, defined in <a href="#Part1" id="rfc.xref.Part1.20"><cite title="Hypertext Transfer Protocol (HTTP/1.1): Message Syntax and Routing">[Part1]</cite></a>, <a href="p1-messaging.html#uri" title="Uniform Resource Identifiers">Section 2.7</a>&gt;
    19531950</pre><p id="rfc.section.B.p.4">The rules below are defined in other parts:</p>
    1954       <div id="rfc.figure.u.15"></div><pre class="inline">  <a href="#imported.abnf" class="smpl">HTTP-date</a>     = &lt;HTTP-date, defined in <a href="#Part2" id="rfc.xref.Part2.9"><cite title="Hypertext Transfer Protocol (HTTP/1.1): Semantics and Content">[Part2]</cite></a>, <a href="p2-semantics.html#http.date" title="Date/Time Formats">Section 7.1.1.1</a>&gt;
     1951      <div id="rfc.figure.u.15"></div><pre class="inline">  <a href="#imported.abnf" class="smpl">HTTP-date</a>     = &lt;HTTP-date, defined in <a href="#Part2" id="rfc.xref.Part2.10"><cite title="Hypertext Transfer Protocol (HTTP/1.1): Semantics and Content">[Part2]</cite></a>, <a href="p2-semantics.html#http.date" title="Date/Time Formats">Section 7.1.1.1</a>&gt;
    19551952</pre><h1 id="rfc.section.C"><a href="#rfc.section.C">C.</a>&nbsp;<a id="collected.abnf" href="#collected.abnf">Collected ABNF</a></h1>
    19561953      <div id="rfc.figure.u.16"></div> <pre class="inline"><a href="#header.age" class="smpl">Age</a> = delta-seconds
     
    21382135                     </ul>
    21392136                  </li>
    2140                   <li><em>Part2</em>&nbsp;&nbsp;<a href="#rfc.xref.Part2.1">2</a>, <a href="#rfc.xref.Part2.2">4</a>, <a href="#rfc.xref.Part2.3">4.1.2</a>, <a href="#rfc.xref.Part2.4">4.1.3</a>, <a href="#rfc.xref.Part2.5">4.3</a>, <a href="#rfc.xref.Part2.6">6</a>, <a href="#rfc.xref.Part2.7">7.3</a>, <a href="#rfc.xref.Part2.8">10</a>, <a href="#Part2"><b>12.1</b></a>, <a href="#rfc.xref.Part2.9">B</a><ul>
    2141                         <li><em>Section 4.2.1</em>&nbsp;&nbsp;<a href="#rfc.xref.Part2.2">4</a>, <a href="#rfc.xref.Part2.6">6</a></li>
    2142                         <li><em>Section 6</em>&nbsp;&nbsp;<a href="#rfc.xref.Part2.3">4.1.2</a></li>
    2143                         <li><em>Section 7.1.1.1</em>&nbsp;&nbsp;<a href="#rfc.xref.Part2.7">7.3</a>, <a href="#rfc.xref.Part2.9">B</a></li>
    2144                         <li><em>Section 7.1.1.2</em>&nbsp;&nbsp;<a href="#rfc.xref.Part2.4">4.1.3</a></li>
    2145                         <li><em>Section 7.2.1</em>&nbsp;&nbsp;<a href="#rfc.xref.Part2.5">4.3</a></li>
     2137                  <li><em>Part2</em>&nbsp;&nbsp;<a href="#rfc.xref.Part2.1">2</a>, <a href="#rfc.xref.Part2.2">2</a>, <a href="#rfc.xref.Part2.3">4</a>, <a href="#rfc.xref.Part2.4">4.1.2</a>, <a href="#rfc.xref.Part2.5">4.1.3</a>, <a href="#rfc.xref.Part2.6">4.3</a>, <a href="#rfc.xref.Part2.7">6</a>, <a href="#rfc.xref.Part2.8">7.3</a>, <a href="#rfc.xref.Part2.9">10</a>, <a href="#Part2"><b>12.1</b></a>, <a href="#rfc.xref.Part2.10">B</a><ul>
     2138                        <li><em>Section 4.2.1</em>&nbsp;&nbsp;<a href="#rfc.xref.Part2.3">4</a>, <a href="#rfc.xref.Part2.7">6</a></li>
     2139                        <li><em>Section 4.3.1</em>&nbsp;&nbsp;<a href="#rfc.xref.Part2.2">2</a></li>
     2140                        <li><em>Section 6</em>&nbsp;&nbsp;<a href="#rfc.xref.Part2.4">4.1.2</a></li>
     2141                        <li><em>Section 7.1.1.1</em>&nbsp;&nbsp;<a href="#rfc.xref.Part2.8">7.3</a>, <a href="#rfc.xref.Part2.10">B</a></li>
     2142                        <li><em>Section 7.1.1.2</em>&nbsp;&nbsp;<a href="#rfc.xref.Part2.5">4.1.3</a></li>
     2143                        <li><em>Section 7.2.1</em>&nbsp;&nbsp;<a href="#rfc.xref.Part2.6">4.3</a></li>
    21462144                     </ul>
    21472145                  </li>
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