weak/strong constraint proposal

[Michael Priestley <mpriestl@ca.ibm.com>]

The following proposal is relative to
the existing constraint design documented here:
http://www.oasis-open.org/committees/download.php/25090/IssueConstraints12008.html

I'm starting with the assumption that
we would want the default or normal behavior to be weak constraints - so
I'm proposing a notation to declare when a constraint should be respected/required
for interoperability, and letting the default be to assume that the constraint
is not required.

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Proposed notation: optionally precede
the normal constraint declaration with an "s" for strong.

Example:
s(topic hi-d basicHighlight-c)

This notation is parallel to the notation
for attribute domains, where a leading "a" is used to identify
the value as having special meaning.

Normally-declared constraints are to
be ignored by conref processing, in order to ease sharing between groups
that have implemented constraints primarily to enforce authoring guidelines,
rather than for strict processing requirements.

If there is a processor or other strong
dependency on a constraint being present, then the constraint can be declared
in the document type with the prefix "s". The constraint should
then be handled in exactly the way currently described in the existing
design.

-------------------- 

Let me know if this is enough - it's
a fairly simple proposal, relative to the existing one :-) But if it would
be useful for me to go in and edit the original, I can. 

Michael Priestley, Senior Technical
Staff Member (STSM)
Lead IBM DITA Architect 
mpriestl@ca.ibm.com
http://dita.xml.org/blog/25