Charset parameter of +xml media types

Hi,

  This is an analysis of what the registration documents of +xml media
types have to say about the charset parameter and/or character encoding
detection. The following types have a charset parameter and simply defer
to application/xml:

  * application/atom+xml
  * application/ccxml+xml
  * application/conference-info+xml
  * application/cpl+xml
  * application/dialog-info+xml
  * application/epp+xml
  * application/kpml-request+xml
  * application/kpml-response+xml
  * application/pls+xml
  * application/rdf+xml
  * application/reginfo+xml
  * application/resource-lists+xml
  * application/rlmi+xml
  * application/rls-services+xml
  * application/samlassertion+xml
  * application/samlmetadata+xml
  * application/simple-filter+xml
  * application/smil+xml
  * application/soap+xml
  * application/spirits-event+xml
  * application/srgs+xml
  * application/ssml+xml
  * application/vnd.llamagraphics.life-balance.exchange+xml
  * application/vnd.mozilla.xul+xml
  * application/vnd.oma.dd2+xml
  * application/vnd.otps.ct-kip+xml
  * application/vnd.sun.wadl+xml
  * application/voicexml+xml
  * application/watcherinfo+xml
  * application/xenc+xml
  * application/xhtml+xml
  * application/xhtml-voice+xml
  * application/xop+xml
  * application/xv+xml

The following types defer to application/xml as above, but they are
restricted to UTF-8:

  * application/xcap-att+xml
  * application/xcap-caps+xml
  * application/xcap-el+xml
  * application/xcap-error+xml
  * application/xmpp+xml

The following types require the charset parameter and allow only the
use of UTF-8:

  * application/shf+xml

The following types have no charset parameter:

  * application/vnd.3gpp.bsf+xml
  * application/vnd.3gpp2.bcmcsinfo+xml
  * application/vnd.criticaltools.wbs+xml
  * application/vnd.irepository.package+xml
  * application/vnd.liberty-request+xml
  * application/vnd.nokia.conml+xml
  * application/vnd.nokia.iptv.config+xml
  * application/vnd.nokia.pcd+xml
  * application/vnd.pwg-xhtml-print+xml
  * application/vnd.uoml+xml
  * application/vnd.wv.csp+xml
  * model/vnd.moml+xml
  * application/vnd.wv.ssp+xml
  * application/vnd.zzazz.deck+xml

The following types have no charset and only UTF-8 is allowed:

  * application/cnrp+xml
  * application/csta+xml
  * application/CSTAdata+xml
  * application/vnd.apple.installer+xml
  * application/sbml+xml
  * application/vnd.solent.sdkm+xml
  * application/vnd.HandHeld-Entertainment+xml
  * application/vnd.nokia.landmarkcollection+xml

The following types explicitly require to ignore charset:

  * application/vnd.apple.installer+xml
  * application/sbml+xml

The following types have a unclear definition including a note that
the encoding and/or the value of the charset parameter defaults to
UTF-8:

  * application/im-iscomposing+xml
  * application/pidf+xml
  * application/poc-settings+xml
  * application/vnd.omads-email+xml
  * application/vnd.omads-file+xml
  * application/vnd.omads-folder+xml
  * application/vnd.syncml+xml
  * application/vnd.nokia.landmark+xml
  * application/beep+xml

The specifications are not always entirely clear about these things,
so some types might not be in the right category. However, only the
first two categories can be considered proper registrations, in my
opinion.

See http://lists.w3.org/Archives/Public/www-tag/2006Sep/0019.html
for a similar analysis with respect to fragment identifiers.
-- 
Björn Höhrmann · mailto:bjoern@hoehrmann.de · http://bjoern.hoehrmann.de
Weinh. Str. 22 · Telefon: +49(0)621/4309674 · http://www.bjoernsworld.de
68309 Mannheim · PGP Pub. KeyID: 0xA4357E78 · http://www.websitedev.de/ 

Received on Tuesday, 5 September 2006 23:44:50 UTC