usefor-usefor-02 November 2004

3.2.12  User-Agent

   The User-Agent header contains information about the user agent
   (typically a newsreader) generating the article, for statistical
   purposes and tracing of standards violations to specific software
   needing correction.  It is intended that this header be suitable for
   use in Email.
   user-agent      =  "User-Agent:" SP 1*product CRLF

   product         =  [CFWS] token [CFWS] [ "/" product-version ]

   product-version =  [CFWS] token [CFWS]

   This header MAY contain multiple product-tokens identifying the agent
   and any subproducts which form a significant part of the posting
   agent, listed in order of their significance for identifying the
   application.
      NOTE: This header supersedes the role performed redundantly by
      experimental headers such as X-Newsreader, X-Mailer,
      X-Posting-Agent, X-Http-User-Agent, and other headers previously
      used on Usenet and in Email for this purpose.  Use of these
      experimental headers SHOULD be discontinued in favor of the
      single, standard User-Agent header.
      NOTE: [RFC2616] describes a similar facility for the HTTP
      protocol.  This specification differs in that "{" and "}" are
      allowed in tokens (<product> and <product-version>) and comments
      are permitted wherever whitespace is allowed.

--- ../usefor-usefor-01/User-Agent.out          September 2004
+++ ../usefor-usefor-02/User-Agent.out          November 2004
@@ -1,15 +1,28 @@
 3.2.12  User-Agent
 
    The User-Agent header contains information about the user agent
-   (typically a newsreader) generating the article for statistical
+   (typically a newsreader) generating the article, for statistical
    purposes and tracing of standards violations to specific software
-   needing correction.  Although not one of the mandatory headers,
-   posting agents SHOULD normally include it.  It is also intended that
-   this header be suitable for use in Email.
-
+   needing correction.  It is intended that this header be suitable for
+   use in Email.
    user-agent      =  "User-Agent:" SP 1*product CRLF
 
    product         =  [CFWS] token [CFWS] [ "/" product-version ]
 
    product-version =  [CFWS] token [CFWS]
+
+   This header MAY contain multiple product-tokens identifying the agent
+   and any subproducts which form a significant part of the posting
+   agent, listed in order of their significance for identifying the
+   application.
+      NOTE: This header supersedes the role performed redundantly by
+      experimental headers such as X-Newsreader, X-Mailer,
+      X-Posting-Agent, X-Http-User-Agent, and other headers previously
+      used on Usenet and in Email for this purpose.  Use of these
+      experimental headers SHOULD be discontinued in favor of the
+      single, standard User-Agent header.
+      NOTE: [RFC2616] describes a similar facility for the HTTP
+      protocol.  This specification differs in that "{" and "}" are
+      allowed in tokens (<product> and <product-version>) and comments
+      are permitted wherever whitespace is allowed.