Question about WXS datatypes ID, IDREF and IDREFS

[Eric van der Vlist <vdv@dyomedea.com>]

Hi,

I'd like a confirmation about the paragraph:

"However, [DTD Compatibility] defines the concept of an ID-type, which
is an additional semantic for datatypes that allows datatypes to have
[XML 1.0] cross-reference semantics. An implementation of [DTD
Compatibility] that supports these guidelines should associate the ID,
IDREF and IDREFS datatypes of [W3C XML Schema Datatypes] with the
ID-types ID, IDREF, and IDREFS respectively."

Does this association includes the constraints which are not enforced by
W3C XML Schema when these datatypes are used in a WXS schema but are
enforced by the DTD compatibility library (namely that these types are
used only in attributes and that all the definitions of an element name
must get these attributes with the same definition if one has)?

This could lead to schemas being valid for a RNG processor supporting
only WXS datatypes and invalid for a RNG processor supporting both DTD
and WXS types.

If that's the case, we should advise to people to use DTD types when
they can (ie when they don't need facets).

If that's not the case, we should rather advise to always use WXS
datatypes.

Thanks

Eric 
-- 
Freelance consulting and training.
                                            http://dyomedea.com/english/
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Eric van der Vlist       http://xmlfr.org            http://dyomedea.com
(W3C) XML Schema ISBN:0-596-00252-1 http://oreilly.com/catalog/xmlschema
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