Bonsaiframework Standard
With modern systems user names are rarely typed. So the recommendation is to use descriptive for user and short names for operating related accounts.
| Account Type | Format | Samle | Reasoning |
|---|---|---|---|
| User | first.last | Tin.Pham | You should be using ssh keys so your account name will often never be typed. |
| System | [purpose][role] | serveradmin | Users will often need to sudo in so the period just slows things down. |
Limitations
POSIX states this about usernames:
To be portable across systems conforming to IEEE Std 1003.1-2001, the value is composed of characters from the portable filename character set. The hyphen should not be used as the first character of a portable user name.
Other than that, portable filename character set is:
A B C D E F G H I J K L M N O P Q R S T U V W X Y Z a b c d e f g h i j k l m n o p q r s t u v w x y z 0 1 2 3 4 5 6 7 8 9 . _ -
So periods are actually allowed.
Ubuntu and Mac OS X Self-Imposed Restrictions
Ubuntu and Mac OS X during install does not allow for a period. Not sure why... need to follow-up and would petition for removing that restriction.
Reference
Main article inspiration - http://askubuntu.com/questions/405638/what-are-the-disadvantages-of-having-a-dot-in-a-user-name