The Pentagon UFO Report, is a United States federally mandated assessment summarizing information regarding unidentified flying objects (UFOs), also known as unidentified aerial phenomenon (UAPs). On June 25, 2021, a nine-page preliminary assessment was issued. It states that the UAPTF (Unidentified Aerial Phenomena Task Force) focused on 144 observations of "unidentified aerial phenomena" by the U.S Armed Forces, mostly from U.S. Navy personnel, from 2004 to 2021. No details are given in the preliminary assessment. The report found that the UAPTF was unable to identify 143 of these objects, but it included five categories of potential explanations; "Airborne Clutter" includes objects like birds and balloons, "Natural Atmospheric Phenomena" includes atmospheric effect like ice crystals, "USG or Industry Developmental Programs" includes US military technology, "Foreign Adversary Systems" includes technologies developed by foreign governments such as Russia or China, and "Other", described as a "catchall" for other explanations.