[Bellman]

A) Circle of equal probability. (CEP)

Quote from Delta 1V use of MIRVS ( multiple independently targeted re-entry vehicles) SS-N-27 Skiff (RSM-5 Makeyev)
The missile uses stellar inertial guidance to provide a circle of equal probability (CEP) of 500m.

''The CEP value is a measure of the accuracy of strike on the target and is the radius of the circle within which half the strikes will impact.'' Naval-Technology.Com.

And:

B) Circular Error of Probability.

''The UK is believed to have purchased 58 x Trident 2D-5 missile bodies from the United States and the range of the missile is believed to be in excess of 9,000 km with a CEP (Circular Error of Probability) of about 100 metres. It is believed that in UK service the Trident II D5 carry eight warheads per missile.'' Royal Navy Site.

And:

C) Contact Evaluation Plot.

'Referring to the so-called Contact Evaluation Plot — a pencil-and-paper graphing of local ships' positions — Mr. Hammerschmidt said: ''He ceased this updating of the CEP because of the number of civilians present."The CEP gives officers and crew a constantly refreshed picture of the submarine's location relative to other ships. It is used as a supplement to electronic displays and periscope sweeps.' The Greeneville Inquiry.

Given a number of meanings the interpretation of the abreviation will be context sensitive.