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xs:QName in Schema 1.1

From: Kay, Michael <Michael.Kay@softwareag.com>
Date: Wed, 4 Dec 2002 15:52:59 +0100
Message-ID: <DFF2AC9E3583D511A21F0008C7E621060453DE5B@daemsg02.software-ag.de>
To: www-xml-schema-comments@w3.org

I noticed that in the draft schema 1.1 requirement there is nothing relating
to the QName data type, which is one of the most problematic data types of

Here are some suggestions:

1. Clarify whether the namespace URI of a QName that is written with no
prefix is the null namespace or the default namespace, or whether it's
entirely up to the application to decide. Possibly, allow this to be
controlled via a facet.

2. Consider providing a lexical representation of QNames that uses the
namespace URI and local name rather than a prefix and local name. For


This would allow applications to construct QName values that don't depend on
the in-scope namespace declarations and that can be safely copied-and-pasted
from one XML fragment to another. It would remove the anomaly that the QName
data type is currently the only data type where a lexical representation
cannot be computed as a function of the value-space value.

Make this the canonical lexical representation of a QName.

This representation could be disallowed in any particular schema by use of
the pattern facet.

Michael Kay
Software AG
Received on Wednesday, 4 December 2002 09:53:08 UTC

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