Then the implementation should look for a catalog in the directory specified by the baseURI of the document, using xcatalog as a relative URI reference. If there is no baseURI, there can be no fallback catalog. Paul's vote may no longer be applicable, since the issue has changed somewhat, and we are no longer asking the same question as he voted on in email. No objections, except some on the casing. No objections to re-opening the issue on the basis of new evidence from yesterday's email.
Norm thinks it is a mistake and has a number of interoperability issues.
It may need to be passed on to another part of the implementation, which would mean it needs to be kept. The output of the catalog processor will be a public identifier. Every other type of urn is treated as a string like other system ids. The chair is empowered to pose this question by email on Monday. Votes due midnight Pacific time Monday.