Re: Using versions instead of XEmacs codenames in User-Agent

["Bjørn Mork" <bmork@dod.no>]

Steve Youngs <steve@youngs.au.com> writes:
> * Reiner Steib <reinersteib+gmane@imap.cc> writes:
>
>   > On Sun, Jan 09 2005, Steve Youngs wrote:
>   >> The default settings should give a User-Agent header similar to the
>   >> one in this message's headers.
>
>   > | User-Agent: Gnus/5.110003 (No Gnus v0.3) SXEmacs/22.1.1 "Aston Martin" (linux)
>
>   > Is a quoted string like "Aston Martin" allowed in RFC 2616?  
>
> ,----[ from RFC 2616 ]
> | 14.43 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
> | 
> | 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 white space. 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. They MUST NOT be
> |    used for advertising or other non-essential information. 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).
> `----
>
> Going by that, using quoted text "like this" should be fine.

No, it isn't.  quoting more from RFC 2616:

       token          = 1*<any CHAR except CTLs or separators>
       separators     = "(" | ")" | "<" | ">" | "@"
                      | "," | ";" | ":" | "\" | <">
                      | "/" | "[" | "]" | "?" | "="
                      | "{" | "}" | SP | HT


>   > Upto now, we had it inside the bracket:
>   > | [...] XEmacs/21.4 (Security Through Obscurity, berkeley-unix)
>
> Yep, however, IMHO, this...
>
>   SXEmacs/22.1.1 (Aston Martin, berkeley-unix)
>
> doesn't look anywhere near as nice as...
>
>   SXEmacs/22.1.1 "Aston Martin" (berkeley-unix)

Maybe.  But it doesn't really matter since the first version uses a
perfectly legal comment while the second is an invalid User-Agent
field.



Bjørn
-- 
Save the Honeywell dps8s!