UA string.

[Jesper Juhl]

Dirk Mueller wrote:

> On Don, 20 Feb 2003, Darin Adler wrote:
> 
[snip]
> 
> would match it more. Is there any spec on UserAgent string formatting?
> 

There is.   RFC 2069 "Hypertext Transfer Protocol -- HTTP/1.1" section 14.42 
(link: http://www.cis.ohio-state.edu/cgi-bin/rfc/rfc2068.html#sec-14.42 )

That section says the following about User-Agent : 

"14.42 User-Agent
 

The User-Agent request-header field contains information about the user
agent originating the request. This is for statistical purposes, the
tracing of protocol violations, and automated recognition of user agents
for the sake of tailoring responses to avoid particular user agent
limitations. User agents SHOULD include this field with requests. The field
can contain multiple product tokens (section 3.8) and comments identifying
the agent and any subproducts which form a significant part of the user
agent. By convention, the product tokens are listed in order of their
significance for identifying the application. 


          User-Agent     = "User-Agent" ":" 1*( product | comment )

 

Example: 


User-Agent: CERN-LineMode/2.15 libwww/2.17b3 "



section 3.8 has this to say : 



"3.8 Product Tokens
 

Product tokens are used to allow communicating applications to identify
themselves by software name and version. Most fields using product tokens
also allow sub-products which form a significant part of the application to
be listed, separated by whitespace. By convention, the products are listed
in order of their significance for identifying the application. 


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

 

Examples: 


User-Agent: CERN-LineMode/2.15 libwww/2.17b3 
 Server: Apache/0.8.4 


Product tokens should be short and to the point -- use of them for
advertising or other non-essential information is explicitly forbidden.
Although any token character may appear in a product- version, this token
SHOULD only be used for a version identifier (i.e., successive versions of
the same product SHOULD only differ in the product-version portion of the
product value). "



/ Jesper Juhl /