ISSUE-367: Clarify initial value override for tts:textAlign

#textAlign clarification

Clarify initial value override for tts:textAlign

State:

CLOSED

Product:

TTML IMSC 1.0

Raised by:

Nigel Megitt

Opened on:

2015-01-27

Description:

The feature list in §7.4 of the IMSC 1 CR specifies for #textAlign:

> MAY be used. The initial value of tts:textAlign shall be "center" for the default region. NOTE: This is consistent with [ST2052-1].

This is somewhat subtle, and doesn't indicate that it's a variation from TTML1SE. I propose the following edited version:

> MAY be used. The initial value of tts:textAlign shall be "center" for the default region only. NOTE: This is consistent with [ST2052-1] but differs from TTML1SE. Document authors are recommended not to rely on the initial value for text alignment in the default region but to specify the tts:textAlign attribute explicitly to generate the expected presentation by both generic TTML1SE and IMSC 1 presentation processors.

I also propose appending this wording to the #layout feature in §6.10:

> NOTE: Authors are recommended to define and reference a region rather than relying on the default region, to avoid inconsistent presentation between generic TTML1SE and IMSC 1 presentation processors resulting from the different initial value of tts:textAlign for the default region. See also #textAlign.

This is an editorial clarification rather than a substantive change.

Related Actions Items:

No related actions

Related emails:

1. Second CR for IMSC1 (from pal@sandflow.com on 2015-05-04)
2. {minutes} TTWG Meeting 2015-04-02 (from nigel.megitt@bbc.co.uk on 2015-04-02)
3. Re: List of changes since the IMSC1 CR (from pal@sandflow.com on 2015-04-02)
4. {agenda} TTWG Meeting 2015-04-02 (from nigel.megitt@bbc.co.uk on 2015-04-01)
5. List of changes since the IMSC1 CR (from pal@sandflow.com on 2015-03-30)
6. {minutes} TTWG Meeting 2015-03-26 (from nigel.megitt@bbc.co.uk on 2015-03-26)
7. {agenda} TTWG Meeting 2015-03-26 (from nigel.megitt@bbc.co.uk on 2015-03-25)
8. {minutes} TTWG Meeting 2015-01-29 (from nigel.megitt@bbc.co.uk on 2015-01-29)
9. {agenda} TTWG Meeting 2015-01-29 (from nigel.megitt@bbc.co.uk on 2015-01-28)
10. Re: ISSUE-367 (#textAlign clarification): Clarify initial value override for tts:textAlign [TTML IMSC 1.0] (from glenn@skynav.com on 2015-01-27)
11. ISSUE-367 (#textAlign clarification): Clarify initial value override for tts:textAlign [TTML IMSC 1.0] (from sysbot+tracker@w3.org on 2015-01-27)

Related notes:

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