to test if the context node is (e.g.) an ns:par element you usually write:

test="self::ns:par"

What's the equivalent for attributes, that is how do you test if the
context node is an ns:attr attribute? Is there a similar concise expression?

With XSLT 2.0 or later
   test="self::attribute(ns:par)"

	Martin Honnen
	http://msmvps.com/blogs/martin_honnen/