Q. How do I create username or user groups in upper case under Linux / *BSD / UNIX operating systems?
You can create username and groups in upper case but I don’t recommend it for following problems:
(a) Confusion – Some user may get confused with username VIVEK and vivek.
(b) Compatibility issues – Many protocols and certain libraries may produced compatibility issues.
The use of upper case letters for usernames or group names should be avoided under Linux / UNIX like operating systems.
2 comment
can be done by upgrading the package shadow-utils, after that you will be able to add the username with upper/lower characters
You use the shift key on the keyboard. I’d say reason ‘a’ is the only one.