I Must Use My Vast Cataloging Powers For Good

According to our tables for constructing call numbers, the part of the call number derived from the title for Fantastic Four should be F3, because 3 is the number assigned to 'a' when it comes after 'f.' But I'm doing the cataloging, so I said, "Pffft, forget that."

It's F4 instead.

Sometimes I am easily amused.