Comments on VoiceXML 2.0 Working Draft 23rd October 2001

Some comments on the VoiceXML 2.0 Working Draft:

1. None of the examples are conforming, according to Appendix F, because 
none of them have a namespace declaration.

2. Section 1.5.1. Since "lang" has been replaced with "xml:lang" between 
VoiceXML 1.0 and 2.0, why has "base" not been replaced with "xml:base"?

3. The glossary does not include entries for:
a) the term "energy", one of the possible values for bargeintype

4. The URI scheme for telephone numbers has changed from "phone:" in 
VoiceXML 1.0 to "tel:" in VoiceXML 2.0, but this is not listed in Appendix J.

5. There is no explicit statement of what a VoiceXML 2.0 processor should 
do when it finds a VoiceXML 1.0 document. Presumably it would be allowed to 
switch to a backwards-compatibility mode?

6. Are ECMAScript objects passed to a subdialog passed by value or by 

7. Section 1.2.4, point 4: "The language has a well-defined semantics..." 
should be "The language has well-defined semantics..."

8. Would it be helpful for the HTTP User-Agent to indicate which version of 
VoiceXML the browser understands? Or is there a better mechanism for this? 
I'm thinking about a scenario where a server is prepared to serve up 
different documents for a VoiceXML 1.0 or a VoiceXML 2.0 processor - is 
there any provision for this?

9. Section 1.2.4, point 1: "For details about XML, refer to the Annotated 
XML Specification". This should refer (at least primarily) to XML 1.0 
Second Edition, The Annotated 
XML Specification is (at the time of writing) based on XML 1.0 1st Edition.

10. I don't think there is any mention of a MIME type for VoiceXML.

11. In Appendix F, "propriety" should be "proprietary".

12. Also in Appendix F, there is a reference to a conforming processor 
throwing 'an "error.unsupported.<element>" event'. Should there also be a 
reference to "error.unsuppported.<attribute>", in the event of a document 
using an unknown attribute as part of a known element?

13. Section 5.2.6, Event Types says

"Errors encountered during document loading" ... "and syntactic errors (no 
XML header, no <vxml> element, etc) result in a badfetch error event"...

I'm not sure what the XML header referred to here is. If it is the XML 
declaration, then I don't believe that its omission is an error. (XML 2.8 
says "XML documents should begin with an XML declaration which specifies 
the version of XML being used.")

Matthew Wilson

Received on Wednesday, 12 December 2001 18:36:50 UTC