452nd Battalion

 was a pre-War battalion of the United States Army stationed in Irvine, California. The battalion was vaporized in the fires of the nuclear war alongside most of Orange County.

Appearances
is mentioned in Fallout: New Vegas, appearing on the dog tag fist. The texture is erroneously used as a stand-in for NCR dog tags, despite the impossibility of it (Irvine and Orange County no longer exist after the war and the New California Republic does not have a 452nd battalion).