Thanks to David Carlisle, and Jenni Tennsion

The combination of your suggestions plus a hack of Chris Bayes 'XML/XSL
Portal' gave me a workable, and (moderately) flexible solution:

I now have one DATA sheet (.xml), one style sheet (.xslt), plus any number
of caller xml sheets (.xml).

The caller (my term but it's ugly); caller xml's are named for their role
(caller_detail.xml, caller_summary.xml &c), and 'know' about the other
sheets in the project.

####################

<?xml-stylesheet type="text/xsl"  href="stylesheet.xslt"?>
<!DOCTYPE top_level_element [
	<!ENTITY main SYSTEM "data.xml">
]>
<top_level_element title="XML Main" id="page">
	<!-- use these nodes to populate the style sheet variables -->
	<!-- in my case, mode controls display -->
	<mode>Detail</mode>

	<!-- this simply gives me a 'project' name for a set of calling
files -->
	<caller>caller_</caller>

	<pagemain>
	&main;
	</pagemain>
</top_level_element>

##########################


Note, this gets around the problem of a large data sheet having hard coded
information - though it breaks my one XML sheet only rule.



Date: Fri, 9 Nov 2001 09:07:43 -0000 
From: Robert Stuart <Robert.Stuart@xxxxxxxxxxxxxxxxx>
Subject: Re:  Change an XSLT top-level parameter

I was hoping for something like ...

[snip]

================

Date: Thu, 8 Nov 2001 17:01:18 GMT
From:  <davidc@xxxxxxxxx>
Subject: Re:  Change an XSLT top-level parameter

> Is there any way I change an XSLT top-level parameter from the client side
> without using java script?

[snip]

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