Updating XML

Hi

I was wondering if there was such a thing as an 'XML Update Specification'.
That is, a standard way of describing a set of modifications to an XML
document, possibly as an XML document itself.

Thinking about it, an XSL stylesheet with the identity transformation and
templates matching the required modifications would be adequate, but has
anyone heard of anything more explicit for this purpose?  I'm thinking in
particular of issuing updates to remote documents using an HTTP POST.

Cheers,
Ben.