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...
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.