Long time lurker, first time commenter... Personally though regardless of how you get there you only want True or False if the function succeeds or fails in deleting the item from the collection. If it doesn't exist it has done neither and you really do need to handle that. It is unlikely that if you carefully created the collection the case of neither happening is highly unlikely but it can, and will, happen. Improper, or worse yet no, error handling is a pox and while it is tedious and annoying the long term benefits to error/exception handling are worth it. If I must pick one though... False, as nothing was deleted. Even in that it should send up a flag somewhere as, presumably, the point is to get rid of the item.

"A foolish consistency is the hobgoblin of little minds, adored by little statesmen and philosophers and divines." - Ralph Waldo Emerson, Essays. First Series. Self-Reliance.