What is an ADIT stamp?
A Lawful Permanent Resident (LPR) may re-enter the United States with a valid Alien Documentation Identification and Telecommunication (ADIT) Stamp.
It is also called I-551 stamp. The ADIT Stamp is provided to a LPR as temporary evidence of his or her resident status.
It may be affixed to a passport or to Form I-94. It is also known as I-551 stamp because it is a “Green Card”