Policy to check if value already exists, then move to next value
The User Logon Name Generation Policy allows you to provide multiple value generation options in case an object exists in the environment with the value already. This policy is only available for generation Logon Name (Pre-Windows 2000), or sAMAccountName; this is not available for other attributes.
Enhancement TF00693654 has been logged for consideration in a future release of the product. Details of the enhancement are to enhance the policy so that it's capable of being used with other attributes, not just sAMAccountName.