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CR003: Use of application/x-www-form-urlencoded

From: Hugo Haas <hugo@w3.org>
Date: Fri, 13 Jan 2006 14:01:39 +0100
To: www-ws-desc@w3.org
Message-ID: <20060113130139.GE10286@w3.org>
Issue CR003, wsdl20-adjuncts vs RFC 4288, points out that part 2
encourages the use and implementation of
application/x-www-form-urlencoded by having
application/x-www-form-urlencoded as a serialization format and
possible value of an attribute:

  6.8.2 Serialization as "application/x-www-form-urlencoded"

  6.3.3 Default input and output serialization format

This media type is of the form */x-*, which RFC 4288 section 3.4

  3.4.  Special x. Tree

     For convenience and symmetry with this registration scheme, subtype
     names with "x." as the first facet may be used for the same purposes
     for which names starting in "x-" are used.  These types are
     unregistered, experimental, and for use only with the active
     agreement of the parties exchanging them.

     However, with the simplified registration procedures described above
     for vendor and personal trees, it should rarely, if ever, be
     necessary to use unregistered experimental types.  Therefore, use of
     both "x-" and "x." forms is discouraged.

     Types in this tree MUST NOT be registered.

Björn has a good point. However, despite its */x-* form,
application/x-www-form-urlencoded is very common on the Web.

It's the default content type for form submission in the HTML 4.01
Recommendation[1], appeared in the HTML specification in version 2.0
(RFC 1866[8] on the IETF standards track), and has been in HTML forms
since Mosaic for X 2.0 introduced them in 1993[6] if I am not
mistaken. It's specified as a serialization format in the XForms 1.0
Recommendation[2]. It's the default media encoding type in the Voice
XML 2.0 Recommendation[3]. It's also the media type used in the SPARQL
Protocol HTTP binding Last Call Working Draft[4]. This list may not be

application/x-www-form-urlencoded is already widely used and
implemented and is therefore a special case in this .x tree.

I therefore recommend closing the issue without action.



  1. http://www.w3.org/TR/1999/REC-html401-19991224/interact/forms.html#h-
  2. http://www.w3.org/TR/2003/REC-xforms-20031014/slice11.html#serialize-urlencode
  3. http://www.w3.org/TR/2004/REC-voicexml20-20040316/#dml5.3.8
  4. http://www.w3.org/TR/2005/WD-rdf-sparql-protocol-20050914/#query-bindings-http
  6. http://archive.ncsa.uiuc.edu/SDG/Software/Mosaic/Docs/fill-out-forms/overview.html
  8. http://ftp.ics.uci.edu/pub/ietf/html/rfc1866.txt
Hugo Haas - W3C
mailto:hugo@w3.org - http://www.w3.org/People/Hugo/

Received on Friday, 13 January 2006 13:01:51 UTC

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