hixie: Clarify how to handle unknown language codes. (whatwg r4454)

hixie: Clarify how to handle unknown language codes. (whatwg r4454)

http://dev.w3.org/cvsweb/html5/spec/Overview.html?r1=1.3553&r2=1.3554&f=h
http://html5.org/tools/web-apps-tracker?from=4453&to=4454

===================================================================
RCS file: /sources/public/html5/spec/Overview.html,v
retrieving revision 1.3553
retrieving revision 1.3554
diff -u -d -r1.3553 -r1.3554
--- Overview.html 19 Dec 2009 01:34:30 -0000 1.3553
+++ Overview.html 19 Dec 2009 02:05:21 -0000 1.3554
@@ -7217,8 +7217,19 @@
   unknown (the empty string).</p>
 
   <p>If the resulting value is not a recognized language code, then it
-  must be treated as an unknown language (as if the value was the
-  empty string).</p>
+  must be treated as an unknown language having the given language
+  code, distinct from all other languages. For the purposes of
+  round-tripping or communicating with other services that expect
+  language codes, user agents should pass unknown language codes
+  through unmodified.</p>
+
+  <p class="example">Thus, for instance, an element with <code title="">lang="xyzzy"</code> would be matched by the selector <code title="">:lang('xyzzy')</code> (e.g. in CSS), but it would not be
+  matched by <code title="">:lang('abcde')</code>, even though both
+  are equally invalid. Similarly, if a Web browser and screen reader
+  working in unison communicated about the language of the element,
+  the browser would tell the screen reader that the language was
+  "xyzzy", even if it knew it was invalid, just in case the screen
+  reader actually supported a language with that code after all.</p>
 
   <hr><p>User agents may use the element's language to determine proper
   processing or rendering (e.g. in the selection of appropriate

Received on Saturday, 19 December 2009 02:06:31 UTC