We use four: ASIS, Dewey, LC, and SuDoc. Our current ILS (which calls this the Class scheme) also creates auto-generated call numbers, like serial numbers, when there is no 050, 082, or 086 in the MARC record. A quick survey found several (880 to be exact) that were out of sync (e.g. Dewey call numbers labeled as if they were auto-generated or vice versa). I don't want to put auto-generated call numbers in the FOLIO database since they aren't relevant so I need to be able to trust the Class scheme label. Most were fixed via API and only a few had to be fixed manually.