Domain

Due to a lack of visibility permission cleanup is performed far less frequently than it could, and probably should. As a result, ghost ACEs (permissions from deleted accounts) linger in the dark corners of the file system, threatening the unsuspecting admin with the horrors of unresolvable SIDs.

When you are planning a migration of user accounts between domains one task always pops up pretty quickly: reassigning the permissions of the users in the source domain to the corresponding users in the target domain, in other words reACLing the file server.