can not create groupnames or usernames with Upper and lower characters to-gether(Ex: XXXggg)

[Padiyath Sreekumaran]

  Hello,

  Iam OS RedHat 3.0. When I run the following command from root account
I get the 

  error:

 

 

l_kumar]$ /usr/sbin/groupadd -g 999888 XXXggg

groupadd: XXXggg is a not a valid group name

 

 

      Thanks in advance,

          Kumar