The 'fake error messages to thwart crackers' thing is pretty relatable - I think back in my day I went with 'early-exit trap (#23)' or the likes for this type of error condition. It does help that we didn't have any phone support - numbers would potentially be painful that way! Another common one I see is dictionary words though even something neutral like 'anteater' or 'weasel' or 'high-jig-south' can both be frustrating to see as a user as well as when trying to deal with support for the inevitable case an integrity check fails on real systems...