Sample wording for conformance provision that allows foreign attributes

Further to my suggestion concerning allowing foreign attributes 
(metadata) while not allowing foreign elements.

I draw the ODF TC's attention to the  XSLT2 Recommendation, which allows 
foreign attributes, for some wording that may be helpful.


3.3 Extension Attributes

[Definition: An element from the XSLT namespace may have any attribute 
not from the XSLT namespace, provided that the expanded-QName 
<http://www.w3.org/TR/2007/REC-xslt20-20070123/#dt-expanded-qname> (see 
[XPath 2.0] <http://www.w3.org/TR/2007/REC-xslt20-20070123/#xpath20>) of 
the attribute has a non-null namespace URI. These attributes are 
referred to as *extension attributes*.] The presence of an extension 
attribute must not cause the final result trees 
<http://www.w3.org/TR/2007/REC-xslt20-20070123/#dt-final-result-tree> 
produced by the transformation to be different from the result trees 
that a conformant XSLT 2.0 processor might produce. They must not cause 
the processor to fail to signal an error that a conformant processor is 
required to signal. This means that an extension attribute must not 
change the effect of any instruction 
<http://www.w3.org/TR/2007/REC-xslt20-20070123/#dt-instruction> except 
to the extent that the effect is implementation-defined 
<http://www.w3.org/TR/2007/REC-xslt20-20070123/#dt-implementation-defined> 
or implementation-dependent 
<http://www.w3.org/TR/2007/REC-xslt20-20070123/#dt-implementation-dependent>.



Cheers
Rick Jelliffe