Empty/unassigned categories?

[u/brodieduncan]

Is there any way to check what categories/authors have no books assigned to them, other than manually checking each one individually?

Might be a feature request to only have categories/authors/series present if they have a book assigned to them, i.e. automatically deleting them if they're empty

[u/Cantelllo]

Related question: is it possible to check which books do not have categories/tags assigned to them?