>   Yes, sorry.  I had just '11.3 in mind.  It explicitly
> treats specially two values for 'xsl:attribute/@name':
> 'xmlns' and 'xml:id'.  I wonder whether 'xml:base' should be
> mentioned too, here.

Well, there's a logical reason for not mentioning it here, which is that as
far as xsl:attribute is concerned, creating an xml:base attribute is exactly
the same as creating any other attribute. It's only when the resulting
attribute is attached to an element that xml:base starts to behave
specially, and that's the subject of section 5.7.1.

Michael Kay
http://www.saxonica.com/