Microsoft's implementation of commenting in Active Directory has always amazed me. In Windows Server 2003, everywhere you look you find wizards and tabs and configuration screens with a location for adding comments. It seems like every little setting in Active Directory could tell its own story through its attached comments.
If you've got a large domain run by lots of Windows administrators or if you've incorporated formalized IT processes, in-object commenting is an excellent way to self-document your environment. Attaching a comment to an Organizational Unit at creation helps large domains understand the purpose and ownership of objects throughout their forests. Those comments can contain information about the creator, the authorizing help desk ticket number and even the reason for the configuration.
With Windows Server 2003 and earlier, this critical part of Active Directory administration has had no such capability to store descriptive information. But that changes with the release of Windows Server 2008, which adds the capability to include comments not only for each Group Policy but also for each individual Group Policy setting as well.
Open any Group Policy within the Group Policy Management Console (GPMC), in Windows Server 2008 and view the properties of an available Group Policy setting. You'll notice a new tab marked Comment in the properties window. Even if your standard practice for managing Active Directory doesn't typically include commenting and documenting, doing so here can be vitally important for helping you understand when and why a configuration was made in the past. Knowing the history and owner of all your Group Policy settings can go far in helping you track down and troubleshoot problems down the road.