When working on the ODF change tracking proposal some prototype software was developed including some schemas.
The first file is a partial RelaxNG schema for the proposed change tracking elements: Media:Delta-format.rng.xml
The RelaxNG (.rng) grammar wasn't really designed to be used stand-alone - it was designed to augment the grammar of the host format, in this particular case the ODF grammar. It was combined with ODF v1.2 CD 5 (CD is committee draft in OASIS terminology) - however the modified version of 1.2CD5 has an OASIS copyright and we don't have permission to post it here.
Another file uses schematron check the validity of the format: Media:Delta-constraints.sch.xml
We used both of these schemas to check our sample files (around 50 sets of ODT test files were hand-crafted) and also our software (XSLT scripts etc) for doing change rollback and other simple operations.
These files originally had .rng and .sch extensions - .xml was added to allow file upload to this wiki.