Comment 2 for bug 1677245

Bill,

That assumption is, currently, unfortunately, incorrect. There are cases where we don't have access to either a definitive control set id, or thesaurus (which is a proxy for control set). If the code where that's the case can be taught find (or maybe prompt for?) a thesaurus or control set, then the assumption can be made true. I suspect we may be able make it work by teaching some code to look at the field-local thesaurus subfield (IIRC that there is such a thing on the bib side), but that will require the cooperation of the cataloger...

HTH.