I'd wager it's mostly fixed string indexes, regular expressions ("\d{2}"), and things like that. Maybe also some people with a "varchar(2)" column in the databa

I'd wager it's mostly fixed string indexes, regular expressions ("\d{2}"), and things like that. Maybe also some people with a "varchar(2)" column in the database. A lot of software is written by junior programmers, not infrequently in a hurry. It's an easy mistake to make and if you've been bitten by it once you'll remember it, but many people have never been bitten by it.