xsl:comment and xsl:pi containing template elements?

In looking at the DTD for the recently released XSL spec I noticed that
besides xsl:element containing template data (character data,
instructions, and result elements), the elements xsl:comment, xsl:pi,
and xsl:attribute can contain template data.

For xsl:comment I can kind of understand how this would be useful.
Through macros you could use this as a sloppy version of ifdefing
output.  For xsl:pi I suppose you could make the same argument.  For
these two elements you open a lot of holes with producing correct
output.  For example, how do you embed a comment within a comment
without escaping (is this the desired way to process output?).  The same
goes for embedding pi's within pi's.

However, how on earth could you have a literal result element inside an
attribute?

It looks like this draft makes things very, very, general as far as the
processing model in which it says that a valid XML document in
conjunction with a valid stylesheet may legally produce illegal output.

Is this the case, can someone clarify this?

Thanx,

Tyler

BTW, thank you XSL designers for having the forethought not to bloat XSL
with an embedded scripting solution.  My faith in XSL has been
rekindled.  Keep up the good work.


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