In What is the interval between Db and D# some of the comments indicate that the interval Db->Eb can be considered as a diminished third. I would think that Fbb (double-flatted F) is a diminished third above Db.
Is there more than one (name for the) note that is a diminished 3rd above Db?
If so, wouldn't this ambiguity exist for all of the other intervals?
Note: I'm aware that in a world of equal temperament, this is kind of moot, but that formally there is a difference between Eb and Fbb.