ACTION-928: X-Device-* HTTP header fields registration


As agreed during last F2F, if we are to keep the X-Device-* HTTP header 
fields, then we'd better register them in the provisional message header 
field registry:

The registration request simply consists of the form at the end of this 
email, where I succinctly explain our reasons to keep the infamous "X-" 

Any comments on the form before I send it to the appropriate IETF 

One thing that may be worth doing before I send the request form is to 
properly define the HTTP header fields in the guidelines. They are 
currently implicitly defined in The definitions should be made 
explicit. What I have in mind is something similar to:

The proper ABNF syntax for the new HTTP header fields would be, using 
both the syntax and the definitions of RFC2616:
  X-Device-User-Agent = "X-Device-User-Agent" ":" 1*( product | comment )
  X-Device-Accept = "X-Device-Accept" ":" #( media-range [ accept-params ] )
  X-Device-Accept-Charset = "X-Device-Accept-Charset" ":" 1#( ( charset 
| "*" )[ ";" "q" "=" qvalue ] )
  X-Device-Accept-Encoding = "X-Device-Accept-Encoding" ":" 1#( codings 
[ ";" "q" "=" qvalue ] )
  X-Device-Accept-Language = "X-Device-Accept-Language" ":" 1#( 
language-range [ ";" "q" "=" qvalue ] )
... or we could find a way to simply state that they just match the 
production rules of their corresponding HTTP header fields as defined in 

What about it?


HTTP header fields registration form
Header field names:
X-Device-User-Agent (request header)
X-Device-Accept (request header)
X-Device-Accept-Charset (request header)
X-Device-Accept-Encoding (request header)
X-Device-Accept-Language (request header)

Applicable protocol:


Author/Change controller:
W3C Mobile Web Best Practices Working Group

Specification document(s): (Working Draft) 
(Editor's Draft)

See section Original Header Field in the documents.

Names were chosen on the basis that there are a already existing and 
deployed convention. Since there is no easy way to transition out of a 
situation where an "X-" prefix has been used for other purpose than a 
purely experimental one, the W3C Mobile Web Best Practices Working Group 
acknowledges that these HTTP header field names are already in use and 
requests that the "X-" prefix be kept.

Received on Wednesday, 15 April 2009 16:00:25 UTC