Queries in KLAS make it easy to find records that meet certain criteria. Unfortunately, it can be harder to search by what isn't there.
Maybe you want to find all of the books by a certain narrator that don't have the Foreign Accent subject heading.
Or maybe you want to find all of your patrons that are Active for cassettes but not for DB.
Computer logic is just not very good at that kind of thing... but there's still a way!
The attached HowTo has step-by-step instructions for comparing two sets of records in Excel, in order to find out which records are missing something. And of course: let us know if you need help!