[VorpalWay]

On other layouts that isn't enough. For example French keyboards are AZERTY, not QWERTY. and here in Sweden we have å, ä and ö next to the (tall) enter key, instead of the symbols US and UK have.

(Side note: those are not a and o with diacretics, they are entirely separate letters in the alphabets of the Nordic countries, with entirely different sounds.)

[macshome]

The product I make deals with passwords. We’ve had several bugs over the years that came down to Unicode usernames and passwords containing unexpected characters. Solving them was simple, we just had to be sure to get the encoding and character sets right, but as an American it was eye opening to find so many people with the Euro symbol in password strings.

[RajT88]

Related, a friend of mine uses a long list of heavy metal band names as one of his unit tests for strings. Says it catches a lot of weird encoding bugs.

[eptcyka]

Well aware, just don’t use them in passwords.