Changeset 2119 for draft-ietf-httpbis/latest/p2-semantics.html

Timestamp:

13/01/13 10:22:41 (10 years ago)

Author:

fielding@…

Message:

Accept-Language: clean up prose and note descending order of priority for equal weights (as defined in RFC4647 and original HTTP); partly addresses #426

File:

• draft-ietf-httpbis/latest/p2-semantics.html (modified) (1 diff)

draft-ietf-httpbis/latest/p2-semantics.html

@@ -1999 +1999 @@
       </p>
       <div id="rfc.figure.u.33"></div><pre class="text">  Accept-Language: da, en-gb;q=0.8, en;q=0.7
-</pre><p id="rfc.section.5.3.5.p.5">would mean: "I prefer Danish, but will accept British English and other types of English". (See also <a href="http://tools.ietf.org/html/rfc4647#section-2.3">Section 2.3</a> of <a href="#RFC4647" id="rfc.xref.RFC4647.2"><cite title="Matching of Language Tags">[RFC4647]</cite></a>)
-      </p>
-      <p id="rfc.section.5.3.5.p.6">For matching, <a href="http://tools.ietf.org/html/rfc4647#section-3">Section 3</a> of <a href="#RFC4647" id="rfc.xref.RFC4647.3"><cite title="Matching of Language Tags">[RFC4647]</cite></a> defines several matching schemes. Implementations can offer the most appropriate matching scheme for their requirements.
-      </p>
-      <div class="note" id="rfc.section.5.3.5.p.7"> 
-         <p> <b>Note:</b> The "Basic Filtering" scheme (<a href="#RFC4647" id="rfc.xref.RFC4647.4"><cite title="Matching of Language Tags">[RFC4647]</cite></a>, <a href="http://tools.ietf.org/html/rfc4647#section-3.3.1">Section 3.3.1</a>) is identical to the matching scheme that was previously defined in <a href="http://tools.ietf.org/html/rfc2616#section-14.4">Section 14.4</a> of <a href="#RFC2616" id="rfc.xref.RFC2616.1"><cite title="Hypertext Transfer Protocol -- HTTP/1.1">[RFC2616]</cite></a>.
-         </p> 
-      </div>
-      <p id="rfc.section.5.3.5.p.8">It might be contrary to the privacy expectations of the user to send an Accept-Language header field with the complete linguistic
+</pre><p id="rfc.section.5.3.5.p.5">would mean: "I prefer Danish, but will accept British English and other types of English". If no quality values are assigned
+         or multiple language tags have been assigned the same quality, the same-weighted languages are listed in descending order
+         of priority. Additional discussion of language priority lists can be found in <a href="http://tools.ietf.org/html/rfc4647#section-2.3">Section 2.3</a> of <a href="#RFC4647" id="rfc.xref.RFC4647.2"><cite title="Matching of Language Tags">[RFC4647]</cite></a>.
+      </p>
+      <p id="rfc.section.5.3.5.p.6">For matching, <a href="http://tools.ietf.org/html/rfc4647#section-3">Section 3</a> of <a href="#RFC4647" id="rfc.xref.RFC4647.3"><cite title="Matching of Language Tags">[RFC4647]</cite></a> defines several matching schemes. Implementations can offer the most appropriate matching scheme for their requirements. The
+         "Basic Filtering" scheme (<a href="#RFC4647" id="rfc.xref.RFC4647.4"><cite title="Matching of Language Tags">[RFC4647]</cite></a>, <a href="http://tools.ietf.org/html/rfc4647#section-3.3.1">Section 3.3.1</a>) is identical to the matching scheme that was previously defined for HTTP in <a href="http://tools.ietf.org/html/rfc2616#section-14.4">Section 14.4</a> of <a href="#RFC2616" id="rfc.xref.RFC2616.1"><cite title="Hypertext Transfer Protocol -- HTTP/1.1">[RFC2616]</cite></a>.
+      </p>
+      <p id="rfc.section.5.3.5.p.7">It might be contrary to the privacy expectations of the user to send an Accept-Language header field with the complete linguistic
          preferences of the user in every request (<a href="#fingerprinting" title="Browser Fingerprinting">Section&nbsp;9.6</a>).
       </p>
-      <p id="rfc.section.5.3.5.p.9">As intelligibility is highly dependent on the individual user, it is recommended that client applications make the choice
-         of linguistic preference available to the user. If the choice is not made available, then the Accept-Language header field <em class="bcp14">MUST NOT</em> be given in the request.
-      </p>
-      <div class="note" id="rfc.section.5.3.5.p.10"> 
-         <p> <b>Note:</b> When making the choice of linguistic preference available to the user, we remind implementers of the fact that users are not
-            familiar with the details of language matching as described above, and ought to be provided appropriate guidance. As an example,
-            users might assume that on selecting "en-gb", they will be served any kind of English document if British English is not available.
-            A user agent might suggest in such a case to add "en" to get the best matching behavior.
+      <p id="rfc.section.5.3.5.p.8">Since intelligibility is highly dependent on the individual user, user agents need to allow user control over the linguistic
+         preference. A user agent that does not provide such control to the user <em class="bcp14">MUST NOT</em> send an Accept-Language header field.
+      </p>
+      <div class="note" id="rfc.section.5.3.5.p.9"> 
+         <p> <b>Note:</b> User agents ought to provide guidance to users when setting a preference, since users are rarely familiar with the details
+            of language matching as described above. For example, users might assume that on selecting "en-gb", they will be served any
+            kind of English document if British English is not available. A user agent might suggest, in such a case, to add "en" to the
+            list for better matching behavior.
          </p> 
       </div>