Purpose

The SIGNIN command enables you to sign in entities that have been signed out. Sign in of an entity releases exclusive rights to that entity, allowing another user or CCID to modify it. In addition, when an entity is signed out, preauthorization commands cannot be executed for that entity. An entity must be signed in before it can be preauthorized.

For example, if you want to modify a map and another user has signed out one of that map's work records, you would not be allowed to regenerate the map. The other user, or someone authorized to sign in entities for that user, would have to do so before you could generate the map.