Using the "Find..." function from the "Action" menu (or right-clicking the domain name) in Active Directory Users and Computers and then opening a user or group object when Quest Authentication Services 4.0.x is installed the "Unix Account" tab is not available. However, when browsing the OU structure and locating the object the "Unix Account" tab is available.
The display specifiers have not been installed.
In Quest Authentication Services 4.0.x Control Center, go to Preferences | Display Specifiers and click on "Register Display Specifiers with Active Directory".
Once installed this option is no longer available.