Advanced Aerospace Threat Identification Program
The Advanced Aerospace Threat Identification Program (AATIP) was an unclassified but unpublicized investigatory effort funded by the United States Government to study unidentified flying objects (UFOs) or unexplained aerial phenomena (UAP). The program was first made public on December 16, 2017.
Source: Wikipedia — Advanced Aerospace Threat Identification Program (CC BY-SA 4.0)