This repo tracks evolution of the XML2RFCv3 RNC grammar, starting with that included in the RFC and updated using this repo as a source.
See annotations in the form of comments on the commits. Currently, I'm focusing on whether the changes are documented in RFC7791bis, whether they appear on its issues list, and whether they are backwards-compatible. Note that I'm not saying much about whether I think the changes are a good idea (for now).
A change to the schema is backwards-compatible if it does not invalidate a document that was valid according to a previous schema, and does not change it semantics.