Which Schematron version does libxml2 implement?

Question

Libxml2 comes with a Schematron module. Since Schematron evolved quite a bit I am wondering what version the libxml2 implementation roughly matches.

Answer 1

From a quick look at the source code, libxml2 uses the namespace http://purl.oclc.org/dsdl/schematron which means ISO Schematron (2006). But there's a TODO comment saying

divergences between the draft and the ISO proposed standard :-(

There don't seem to be any changes to the source code that address this. So it's possible that libxml2 only supports a draft version of the ISO standard (maybe Schematron 1.6?). I'd suggest to ask on the libxml2 mailing list to get a definite answer.