> This is because such a mechanism isn't strictly within the 
> confines of XSLT, having to do with processing architectures 
> and not transformations. To standardize a mechanism would 
> necessarily favor one sort of platform, environment or 
> framework, so the best a spec can do is make it optional or 
> leave it out entirely.

Although the XSLT 2.0 spec leaves the semantics of collection URIs
implementation-defined, I think there it is  reasonable to expect that
processors working on a hierarchic filestore will be able to map a folder or
directory to a collection URI. The details of how this works may differ
slightly, so you would be well advised to parameterize the collection URI
(by passing it in as a stylesheet parameter), but apart from that caveat, I
think you can hope for a reasonable level of portability using this
mechanism.

Of course, as with document(), there may be cases where it doesn't work -
for example in a browser with no access to client filestore.

Michael Kay
http://www.saxonica.com/