>>        <xsl:template match="//topic">
>                             ^^^^
>
>  BTW, this is never needed in a pattern.  Just write "topic".

In XSLT1 it's never needed, in XSLT2 the same is probably true although
it does match different elements in that case.

match="//topic" 

would not match a an element in a tree that was rooted at an element
node rather than a document node.

David