In T94959, the message antispoof-noletters has been changed from "Does not contain any letters" to "Usernames must contain one or more characters." as "not all languages use letters". However, it may introduce more confusion. In computing, the word "characters" often means not only letters but also digits and punctuation, which are what AntiSpoof is meant to exclude here.

Perhaps we should reword it to something like "Usernames must not consist only of digits or punctuation."