[Bug 5487] Special status of namespaces xs, xsi, xml etc

http://www.w3.org/Bugs/Public/show_bug.cgi?id=5487

           Summary: Special status of namespaces xs, xsi, xml etc
           Product: XML Schema
           Version: 1.0/1.1 both
          Platform: PC
        OS/Version: Windows XP
            Status: NEW
          Severity: normal
          Priority: P2
         Component: Structures: XSD Part 1
        AssignedTo: cmsmcq@w3.org
        ReportedBy: mike@saxonica.com
         QAContact: www-xml-schema-comments@w3.org


There is currently a clause making it illegal to declare an attribute in the
xsi namespace. However, it doesn't appear to be illegal to declare elements or
other components in this namespace. Is there any good reason why not?

This raises questions about other namespaces with a special status.

Presumably schema processors are expected to be able to process the S4SD
(though one might imagine circumstances in which they cannot process it, for
example if they cannot handle 20-digit integers). But what are they expected to
do if presented with a schema document similar to the S4SD but slightly
different, for example one that defines xs:long with a different range of
values? I think that the right answer here is "all bets are off" - the effect
is undefined.

What about schemas for the xml and xmlns namespaces? The right answer for "xml"
seems to be the same as for "xs" - if a schema document is presented for this
namespace then it should match the W3C specifications for names in that
namespace, and if it doesn't, the effect is undefined. For "xmlns" I think the
rule is different - this namespace has such fundamental significance that any
attempt to declare components in this namespace should be an error.

Received on Monday, 18 February 2008 00:53:21 UTC