Sun Java System Access Manager 7.1 Administration Reference

User Alias

This attribute must be enabled if you create a policy to protect a resource whose subject's member in a remote Directory Server aliases a local user. This attribute must be enabled, for example, if you create uid=rmuser in the remote Directory Server and then add rmuser as an alias to a local user (such as uid=luser) in Access Manager. When you login as rmuser, a session is created with the local user (luser) and policy enforcement is successful.