AATIP (Advanced Aerospace Threat Identification Program).

The Advanced Aerospace Threat Identification Program is the name popularized in 2017 (via Luis Elizondo and a New York Times article) for a Pentagon UAP effort; the Pentagon later acknowledged a program existed but disputed Elizondo's claimed leadership role. In practice it overlaps with, and is often used interchangeably for, the formally contracted AAWSAP. It matters as the public-facing label that triggered the modern disclosure era.