Can you break out the common templates/variables/params into separate XSL documents? This way you can directly target your unique circumstance. For example, what i do is have a global_defintions.xsl that includes all the common XSLT documents (variables, params) that have common usage. Then in the unique XSLTs, I just include global_defintions.xsl. When you need the unique view you call the unique XSLT doc which includes the common stuff.

Well, in a way, my a.xsl is like your global_definitions.xsl: stylesheets
for unique circumstances (e.g., b.xsl) indeed include this base
stylesheet.  The problem lies in how the two need to be combined
(explained and examplified in my previous message) under the restrictions
in place:

a.xsl has to be independent of b.xsl, and b.xsl has to inherit the
a-specific information from a.xsl.  Additionally, a.xsl should be able to
transform a document on its own; it's not just a "library-stylesheet".