What are your favorite fictional acronyms?

Acronyms like:
Library Computer Access/Retrieval System)
LCARS . From Star Trek.

Or T.A.R.D.I.S. “Time and Relative Dimensions in Space.” From Dr. Who?

Or S.H.I.E.L.D. (Strategic Homeland Intervention, Enforcement, and Logistics Division)? From the Marvel universe.

List more of favorite fictional acronyms