- From: CVS User rfieldin <cvsmail@w3.org>
- Date: Tue, 03 Feb 2015 00:32:19 +0000
- To: public-tracking-commit@w3.org
Update of /w3ccvs/WWW/2011/tracking-protection/drafts
In directory gil:/tmp/cvs-serv14627
Modified Files:
tracking-dnt.html
Log Message:
mark the DNS-extension feature at-risk and isolate it within its own subsection
--- /w3ccvs/WWW/2011/tracking-protection/drafts/tracking-dnt.html 2014/12/17 20:27:06 1.277
+++ /w3ccvs/WWW/2011/tracking-protection/drafts/tracking-dnt.html 2015/02/03 00:32:19 1.278
@@ -75,6 +75,14 @@
<a href="http://www.w3.org/2011/tracking-protection/track/issues/postponed">postponed</a>
issues regarding this document.
</p>
+ <p>
+ The following features are at risk and may be cut from the
+ specification during its CR period if there are no (correct)
+ implementations:
+ </p>
+ <ul>
+ <li><a href="#dnt-extensions">DNT-extension</a></li>
+ </ul>
</section>
<section>
@@ -424,6 +432,7 @@
<p>
The <dfn>DNT</dfn> header field is a mechanism for expressing the
user's tracking preference in an HTTP request ([[!RFC7230]]).
+ At most one DNT header field can be present in a valid request.
</p>
<pre class="abnf">
<dfn>DNT-field-name</dfn> = "DNT"
@@ -459,38 +468,46 @@
DNT: 1
</pre>
- <p>
- The remainder of the field-value, after the initial character,
- is reserved for future extensions. DNT extensions can only be
- transmitted when a tracking preference is <a>enabled</a>.
- </p>
- <pre class="abnf">
+ <section id='dnt-extensions'>
+ <h3>DNT Extensions</h3>
+
+ <p>
+ The remainder of the DNT field-value, after the initial character,
+ is reserved for future extensions. DNT extensions can only be
+ transmitted when a tracking preference is <a>enabled</a>.
+ The extension syntax is restricted to visible ASCII characters that
+ can be parsed as a single word in HTTP and safely embedded in a
+ JSON string without further encoding
+ (<a href="#status-representation" class="sectionRef"></a>).
+ </p>
+ <pre class="abnf">
<dfn>DNT-extension</dfn> = %x21 / %x23-2B / %x2D-5B / %x5D-7E
; excludes CTL, SP, DQUOTE, comma, backslash
- </pre>
- <p>
- For example, additional characters might indicate modifiers to the
- main preference expressed by the first digit, such that the main
- preference will be understood if the recipient does not understand
- the extension. Hence, a field-value of "1xyz" can be thought of
- as <q>do not track, but if you understand the refinements defined by
- x, y, or z, then adjust my preferences according to those
- refinements.</q>
- </p>
- <p>
- User agents that do not implement DNT extensions MUST NOT send
- DNT-extension characters in the DNT field-value.
- Servers that do not implement DNT extensions SHOULD ignore anything
- beyond the first character.
- </p>
- <p class="note">
- The extension syntax is restricted to visible ASCII characters that
- can be parsed as a single word in HTTP and safely embedded in a
- JSON string without further encoding
- (<a href="#status-representation" class="sectionRef"></a>).
- At most one DNT header field can be present in a valid
- request [[!RFC7230]].
- </p>
+ </pre>
+ <p>
+ For example, additional characters might indicate modifiers to the
+ main preference expressed by the first digit, such that the main
+ preference will be understood if the recipient does not understand
+ the extension. Hence, a field-value of "1xyz" can be thought of
+ as <q>do not track, but if you understand the refinements defined by
+ x, y, or z, then adjust my preferences according to those
+ refinements.</q>
+ </p>
+ <p>
+ User agents that do not implement DNT extensions MUST NOT send
+ DNT-extension characters in the DNT field-value.
+ Servers that do not implement DNT extensions SHOULD ignore anything
+ beyond the first character.
+ </p>
+ <p class="note">
+ The DNT-extension feature is considered <em>at-risk</em>.
+ Since no extensions have been defined, implementors that don't
+ read specifications are likely to assume that DNT only has the
+ fixed values of "0" or "1". Furthermore, the potential benefits
+ of this mechanism are unclear given that extension information
+ could be supplied using separate request header fields.
+ </p>
+ </section>
</section>
<section id='js-dom'>
@@ -512,15 +529,10 @@
<code>window</code>, in the browser context of the current
<strong>top-level origin</strong>.
The value is <code>null</code> if no DNT header field would be
- sent (e.g., because a tracking preference is <a>not enabled</a>).
- </dd>
- </dl>
- <p class="note">
- Note that the value includes not only the "0" or "1", but also
- any DNT-extension; if no DNT header is sent, the return value is
- <code>null</code>, not an empty string (which would indicate that
- a header is sent with no <a>DNT-field-value</a>).
- </p>
+ sent (e.g., because a tracking preference is <a>not enabled</a>);
+ otherwise, the value is a string beginning with "0" or "1",
+ possibly followed by DNT-extension characters.</dd>
+ </dl>
</section>
<section id='other-protocols'>
Received on Tuesday, 3 February 2015 00:32:20 UTC