Sign

A fixture or area containing lettering or logos used to advertise a store, goods, or services.

To attach a unique electronic signature, derived from the sender's user ID, to a document or field when a document is mailed. Signing mail ensures that if an unauthorized user creates a new copy of a user's ID, the unauthorized user cannot forge signatures with it. In addition, the signature verifies that no one has tampered with the data while the message was in transit.