@Gail, I think you have the right classification there. If anything, the cause was a "type mismatch". You can't really say that "IVAN YEARS" was invalid, only that it was nonsense in the context it was found.

@jim, Yes, I've come across situations like that too. Data migrations are a time when the dirty data gets found. They are also a time when dirty data gets created too. I agree with your suggestion that lookup tables are a good thing. Anywhere that a screen has a field which says or implies "Type of..." and the entry is not something pre-determined or constrained makes me suspicious. Of course, thinking that way is one thing, convincing other people is quite another.;-)