While researching a very weird bug0 in Koha I had to figure out a way chop a string to a specific maximum length. In bytes and not in characters, because in that case the horrible format USMARC is used, whose spec starts with two red flags: It's from January 2000, and it's an "implementation of the American national standard", so you can bet that it only works (well) with ASCII and will be ... interesting when handling Unicode. But it's generally broken for longer strings1.
