- From: Roy T. Fielding <fielding@gbiv.com>
- Date: Mon, 31 Oct 2011 16:35:35 -0700
- To: "public-tracking@w3.org Group WG" <public-tracking@w3.org>
Julian Reschke suggested online that comma should be excluded to
avoid confusion with header recombining in HTTP. The following
change is now in the TPE spec.
....Roy
Index: tracking-dnt.html
===================================================================
RCS file: /w3ccvs/WWW/2011/tracking-protection/drafts/tracking-dnt.html,v
retrieving revision 1.28
retrieving revision 1.29
diff -u -r1.28 -r1.29
--- tracking-dnt.html 28 Oct 2011 09:22:26 -0000 1.28
+++ tracking-dnt.html 31 Oct 2011 23:11:47 -0000 1.29
@@ -281,7 +281,7 @@
<pre class="abnf">
DNT-field-name = "DNT" ; case-insensitive
DNT-field-value = ( "0" / "1" ) *DNT-extension ; case-sensitive
-DNT-extension = %x21-7E ; any visible ASCII
+DNT-extension = %x21-2B / %x2D-7E ; visible ASCII except ","
</pre>
<p>
The DNT field-value sent by a user agent MUST begin with the
@@ -330,7 +330,10 @@
as <q>DNT is enabled, but if you understand the refinements defined
by x, y, or z, then adjust my preferences according to those
refinements.</q> Extensions can only transmitted if the user has
- <a>enabled</a> DNT.
+ <a>enabled</a> DNT. The extension syntax excludes the comma (",")
+ character in order to to differentiate valid field values from an
+ invalid occurrence of multiple DNT header fields that have been
+ combined as a single comma-separated list by a generic HTTP parser.
</p>
<p class="note">
Designers of future extensions should note that, once enabled by
Received on Monday, 31 October 2011 23:36:06 UTC