Rules for Array Group Names on the Active Directory
You might want to plan the groups that you want to create on the Active Directory beforehand because group names cannot be changed after the group is created.
It is not recommended that you use special characters in group names.
NOTE: If you try to add a group (from systems prior to Windows 2000) with a
name that contains special characters, the special characters are replaced with
underscores (_). Whenever you use that group name, you must use the version of the group
name that includes the underscores. The group name that contains special characters is
not valid.
You must log in to the array using the pre-Windows 2000 logon name that is shown in the Account tab of the Active Directory server user property page.