There have been at least as many acronyms and designations assigned to current, past and future kill vehicles of the Ground-based Midcourse Defense (GMD) national missile defense system as there have been successful intercept tests of such kill vehicles. Below I summarize the most important of these kill vehicle designations.
EKV CE-0: This designation covers the kill vehicles used in the first seven GMD intercept tests, from 1999 to 2002, as well as the IFT-1a and IFT-2 fly-by tests in 1998-99. The first, and so far only, place I have seen this designation is on the slides used by MDA Director Admiral Syring during his August 13 presentation at the 2014 Space and Missile Defense Conference. (These slides were obtained via FOIA by Laura Grego of the Union of Concerned Scientists.) These kill vehicles are sometimes referred to as “prototypes” although this term is sometimes also used for the later CE-I and CE-II kill vehicles as well. The “CE” stands for Capability Enhancement, so the CE-0 designation seems to be both a retroactive designation as well as a catch-all for all the early GMD kill vehicles, as indicated by its use for both the fly-by tests, which used two completely different competing kill vehicle designs.