Security Identifier (SID) History is a useful mechanism in Active Directory (AD) migrations. It allows users and groups in a new domain to retain access to resources that still rely on permissions from the old domain. However, once migrations are completed, these historical SIDs can become clutter, posing both security and administrative challenges. While it’s best to remove unnecessary SID History as soon as you’re done migrating, many environments skip this step. Over time, decommission...