ISSUE-252: Prose defining mutual exclusive uses of <metadata> should use must keyword.

metadata exclusive uses

Prose defining mutual exclusive uses of <metadata> should use must keyword.

State:
CLOSED
Product:
TTML 1.0
Raised by:
Glenn Adams
Opened on:
2013-06-04
Description:
In Section 12.1.1 appears:

"Metadata information may be expressed by a metadata element in one of two (non-mutually exclusive) manners: (1) by specifying one or more metadata attributes on the metadata element, and (2) by specifying one or more child elements in the metadata element that express metadata. Both types of metadata are referred to in this document as metadata items."

By using "may" in this normative prose, a reader may fail to notice that this mutual exclusive usage definition has the intended force of "must" in the sense that a given metadata element MUST NOT express metadata attributes and metadata element child elements.

To make this clear, the prose should be modified to read as follows:

"A metadata element must not express metadata information by both (1) specifying one or more metadata attributes and (2) specifying one or more metadata child elements. Both types of metadata are referred to in this document as metadata items."

"Note: In other words, a metadata element may specify, in a mutually exclusive manner, either (1) metadata attributes or (2) metadata child elements, but it may not specify both forms of metadata information together."

Note also that this constraint is not expressible in either XSD or RNC schemas, and must be verified during a semantics verification phase independently from schema validity assessment.
Related Actions Items:
No related actions
Related emails:
  1. Minutes - 2013-06-20 (from glenn@skynav.com on 2013-07-11)
  2. Minutes - 2013-06-27 (from glenn@skynav.com on 2013-07-11)
  3. [minutes] Timed Text call June 20, 2013 (from plh@w3.org on 2013-06-27)
  4. RE: TTML Agenda for 26/06/13 (from mdolan@newtbt.com on 2013-06-27)
  5. TTML Agenda for 26/06/13 (from Sean.Hayes@microsoft.com on 2013-06-27)
  6. Re: TTML 1.0 Issues - Newly Moved to Pending Review (from glenn@skynav.com on 2013-06-20)
  7. Re: TTML 1.0 Issues - Newly Moved to Pending Review (from glenn@skynav.com on 2013-06-20)
  8. TTML Agenda for 20/06/13 -- update -- (from Sean.Hayes@microsoft.com on 2013-06-19)
  9. RE: Issue 252. (from Sean.Hayes@microsoft.com on 2013-06-19)
  10. Re: Issue 252. (from glenn@skynav.com on 2013-06-19)
  11. Re: TTML 1.0 Issues - Newly Moved to Pending Review (from glenn@skynav.com on 2013-06-19)
  12. Issue 252. (from Sean.Hayes@microsoft.com on 2013-06-19)
  13. Re: TTML 1.0 Issues - Newly Moved to Pending Review (from glenn@skynav.com on 2013-06-19)
  14. Re: TTML 1.0 Issues - Newly Moved to Pending Review (from glenn@skynav.com on 2013-06-19)
  15. Re: TTML 1.0 Issues - Newly Moved to Pending Review (from glenn@skynav.com on 2013-06-19)
  16. TTML 1.0 Issues - Newly Moved to Pending Review (from glenn@skynav.com on 2013-06-19)
  17. ISSUE-252 (metadata exclusive uses): Prose defining mutual exclusive uses of <metadata> should use must keyword. [TTML 1.0] (from sysbot+tracker@w3.org on 2013-06-04)

Related notes:

Fixed. https://dvcs.w3.org/hg/ttml/rev/8bc32ff74e24

Glenn Adams, 19 Jun 2013, 07:51:47

Reverted change in https://dvcs.w3.org/hg/ttml/rev/70165fde28e1. Change prose to explicitly admit both metadata attributes and metadata child elements.

Glenn Adams, 27 Jun 2013, 15:45:49

PAL: P2

Philippe Le Hégaret, 24 Oct 2013, 15:57:58

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David Singer <singer@apple.com>, Nigel Megitt <nigel.megitt@bbc.co.uk>, Chairs, Thierry Michel <tmichel@w3.org>, Philippe Le Hégaret <plh@w3.org>, Staff Contacts
Tracker: documentation, (configuration for this group), originally developed by Dean Jackson, is developed and maintained by the Systems Team <w3t-sys@w3.org>.
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