The pipe '|' operator: Does it mean Or or Union?

I've noticed the the Muenchian method uses '|' and that everyone refers
to this as a Union.  However, I also read that this

<xsl:template match="foo | foobar">

means to match the foo OR foobar elements.  Does the definition of the
operator change based on the application?


 XSL-List info and archive:  http://www.mulberrytech.com/xsl/xsl-list