The Voice Browser Working Group (VBWG) is now completing its resolution of issues raised during the review of the Candidate Recommendation version of VoiceXML 2.1 . Our apologies that it has taken so long to respond.
Following the process described in  for advancement to Proposed Recommendation, this is the VBWG's formal response to the issue you raised, identified as '111-6':
Although the media types listed in Appendix E of VoiceXML 2.0 aren't formally registered, they are widely used in the industry, and the VBWG would be remiss not to acknowledge their existence. In addition, the requirements of VoiceXML 2.1 are to specify a small set of features widely used in the industry today that do not break backwards compatibility with the VoiceXML 2.0 specification.
Please indicate before 14 November 2005 whether you are satisfied with the VBWG's resolution, whether you think there has been a misunderstanding, or whether you wish to register an objection.
If you do not think you can respond before 14 November, please let me know. The Director will appreciate a response as to whether or not you agree with the resolution. However, if we do not hear from you at all by 14 November 2005, we will assume that you accept our resolutions.
From: [hidden email] [mailto:[hidden email]] On Behalf Of Bjoern Hoehrmann
Sent: Sunday, June 26, 2005 2:16 PM
To: [hidden email] Subject: VoiceXML 2.1: unregistered audio media types
Dear Voice Browser Working Group,
http://www.w3.org/TR/2005/CR-voicexml21-20050613/ encourages use of non-standard media types like audio/x-wav and audio/x-alaw-basic. It is inappropriate for W3C specifications to encourage use of such types. I see three ways to resolve this, the requirement to support these types is removed, more suitable media types are identified and required instead of the non-standard ones, or W3C registeres the media types for use in the specification.
* Matt Oshry wrote:
>Although the media types listed in Appendix E of VoiceXML 2.0 aren't
>formally registered, they are widely used in the industry, and the VBWG
>would be remiss not to acknowledge their existence. In addition, the
>requirements of VoiceXML 2.1 are to specify a small set of features
>widely used in the industry today that do not break backwards
>compatibility with the VoiceXML 2.0 specification.