Re: [SVGMobile12] Error handling is a "SHOULD"?

Dear Ian,

This is the SVG Working Group response to your comment found at:
   http://lists.w3.org/Archives/Public/www-svg/2005May/0144.html

With more recent versions of the SVG spec, we have changed the wording and 
believe it addresses the problems that have been identified. It now says:

-------------------
When a document is in error, the User Agent shall provide a highly 
perceivable indication of error. The following error handling behavior 
represents a recommended approach that User Agents may choose to implement:

    * The document should be rendered up to, but not including, the first 
element ...
-------------------

Therefore, regarding a highly perceivable warning, the spec has been 
changed as you have suggested to SHALL instead of SHOULD. However, the 
exact mechanism for stopping the rendering is just a "recommended 
approach", not a requirement. We did not feel it was appropriate to define 
a required approach to error handling because implementation experience 
shows that this is a difficult implementation area, and legislating a 
particular error handling mechanism here might raise a significant barrier 
towards achieving good multimedia rendering performance. Also, SVG Tiny is 
targeting constrained devices, which provides extra challenges to 
implementers. Finally, we believe that the primary objective of the 
specification is to tell content developers how to create conformant 
content and implementers how to render conformant content. It is not a 
requirement that the specification attempt to achieve exact and perfect 
user agent behavioral interoperability for how user agents should operate 
against non-conformant content beyond "highly perceivable warning."

Thank you for your feedback. Please let us know if this does not address 
your concerns. We will assume that you accept this response if two weeks 
pass without further postings on this subject.

Jon Ferraiolo
Adobe Systems, Inc.