One of my previous bosses didn't believe in non-ASCII characters because he felt they were "invalid". For some reason, he thought that latin1 database encoding was "standard" and that utf8mb4 is some kind of hack. I explained to him why we should support UTF-8, but he wouldn't hear it.

Instead of migrating the database to use utf8mb4, he had me strip out the "invalid" characters from user input, which I wrote as Rack middleware if I remember correctly. Either the characters would be replaced by their closest ASCII cousins or get removed entirely.

This was totally unnecessary and made it impossible for the product to support other languages.

I imagine there are other bosses just like him out there who think it's "invalid" when someone uses characters other than A-z in their passwords, and told the engineers to do what I did for things like your printer.

Today, I learned why printers get taken over so much. The brute force dictionary is much smaller

No, it's because they don't blocker attackers after finite attempts, and often have default or blank passwords

Enter internationalization... äüöß is just the beginning.