RE: ISSUE-274 (prohibited-semantics): Semantics of "prohibited" features [TTML2]

Although I personally would interpret the spec as requiring the processor’s semantic support for the initial value (as worded now or as proposed), I think it would be clearer to explicitly state this.

 

                Mike

 

From: Glenn Adams [mailto:glenn@skynav.com] 
Sent: Monday, August 19, 2013 8:50 PM
To: Timed Text Working Group
Subject: Re: ISSUE-274 (prohibited-semantics): Semantics of "prohibited" features [TTML2]

 

 

On Mon, Aug 19, 2013 at 9:26 PM, Timed Text Working Group Issue Tracker <sysbot+tracker@w3.org> wrote:

ISSUE-274 (prohibited-semantics): Semantics of "prohibited" features [TTML2]

http://www.w3.org/AudioVideo/TT/tracker/issues/274

Raised by: Pierre-Anthony Lemieux
On product: TTML2

(Draft) TTML 2 states that "In addition, a feature or extension may be specified as prohibited, in which case it must not appear in or be used by a Document Instance, and, if it does appear, may result in the Document Instance being rejected or processing otherwise aborted."

A feature such as #overflow states that "A TTML transformation processor supports the #overflow feature if it recognizes and is capable of transforming all defined values of the tts:overflow attribute."

How does one specify that only the default value of tts:overflow shall be used, i.e. that a document instance shall not contain tts:overflow declarations but that the TTML processor shall use the default value of tts:overflow?

 

I'll remove the "or be used by", which should fix your concern. When I wrote it, I was not including the processor use of a default non-specified value in "use".