Office Communications Server 2007 R2, Office Communications Server 2007 and Live Communications Server 2005 SP1 update the display specifiers in an Active Directory forest. When you upgrade to an Active Directory forest in Windows Server 2008 R2, new locales are added to the forest. Therefore, new display specifiers are also added.
When you run the Prep Forest option in the deployment tool for Office Communications Server 2007 R2, Office Communications Server 2007 or Live Communications Server 2005, the CheckForestPrepState action makes sure that the tab for Office Communications Server 2007 R2, Office Communications Server 2007 or Live Communications Server 2005 exists on each display specifier. If the display specifier does not exist on each tab, the CheckForestPrepState action reports that the forest must be re-mapped.