The cos01 version [and for that matter all versions since csprd03] contain many occurrences of the W3C ITS namespace with a typo.
The correct namespace identification string per the ITS 2.0 normative reference https://www.w3.org/TR/its20/ is:
Misstyped ocurrences are "https://www.w3.org/2005/11/its" or "https://www.w3.org/2005/11/its/"
This is a very important typo to fix. We have indeed 11 wrong occurrences against 15 correct occurrences in the prose spec, importantly all correct in validation artifacts..
Without doubt this already had caused confusion in at least one implementer..