Though I have not yet found outside verification, the theory (was it Kimberly or Demetria?) that the "Apoc" was short for "Apocalypse" would seem to be correct as Apoc was supposedly famous, according to Wikia Entertainment (http://matrix.wikia.com/wiki/Apoc) for writing a virus called "The Four Horsemen" as in "The Four Horsemen of the Apocalypse". I have not verified this in the film and do not know where Wikia got that information. According to Wikipedia, there was also a famous club in Berlin called "The Matrix" that featured a mural of "The Four Horsemen" holding musical instruments that might have been painted by the members of the band Jefferson Airplane, later called Jefferson Starship(http://en.wikipedia.org/wiki/The_Matrix_(club)).
C. Jason Smith, Ph.D. is Professor of English at the City University of New York-LaGuardia CC. He has published books and articles on gender in science fiction film and fantasy and is an active science and technology writer.