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Re: Omission in <element> constraint in Schema Structures spec

From: Henry S. Thompson <ht@cogsci.ed.ac.uk>
Date: 05 Mar 2001 16:29:22 +0000
To: mhuffman@ca.ibm.com
Cc: www-xml-schema-comments@w3.org
Message-ID: <f5bn1b0tc0t.fsf@cogsci.ed.ac.uk>
mhuffman@ca.ibm.com writes:

> The XML Schema Structures spec has a constraint on <element>s whose parent
> is not <schema> which reads:
>  If ref is present, then all of <complexType>, <simpleType>, <key>,
>  <keyref>, <unique>, nullable(nillable), default, fixed, block and
>  type must be absent, i.e. only minOccurs, maxOccurs, id are allowed
>  in addition to ref, along with <annotation>.
> This is in "Schema Representation Constraint: Element Declaration
> Representation OK" (CR spec section 4.3.2 ... Current (Feb 10/2001) spec
> section 3.3.3).  This constraint omits the 4 other attributes of <element>
> - abstract, final, form, and substitutionGroup.
> My assumption is that these 4 attributes also "must be absent" if ref is
> present, otherwise the schema would be in error.

That those attributes are forbidden is enforced by the schema for
schemas.  The explicit representation constraints in the relevant
(sub-)sections are all introduced as being _in addition_ to the
constraints in the SforS.

  Henry S. Thompson, HCRC Language Technology Group, University of Edinburgh
          W3C Fellow 1999--2001, part-time member of W3C Team
     2 Buccleuch Place, Edinburgh EH8 9LW, SCOTLAND -- (44) 131 650-4440
	    Fax: (44) 131 650-4587, e-mail: ht@cogsci.ed.ac.uk
		     URL: http://www.ltg.ed.ac.uk/~ht/
Received on Monday, 5 March 2001 11:29:25 UTC

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