In the new user dialog, there are instructions about characters that can be contained in a username:
> Username must consist of:
>   ➣ lower case letters from the English alphabet
>   ➣ digits
>   ➣ any of the characters ".", "-" and "_"

A user reported the phrasing can be misleading, as it may be understood as meaning that the username *must* contain all of these characters. This is indeed a common pattern on some website giving access to sensitive data, to force user to have a number and an upper case letter in their username.

Reporter suggested changing the wording to "User name may be formed by using the following characters:". We could also simply change it to "Username must only consist of:".

Translations could probably be kept as-is since they have likely rephrased the whole think to be meaningful (at least that's what I'm seeing in French).

This string is at
panels/user-accounts/um-account-dialog.c:195