S-III

The CPOMZ file found on Colonel James Ackerson's computer was discovered in CASTLE Base by Dr. Halsey. The file contained star charts. It was found in a file called S-III, and was found along with another file called KING UNDER THE MOUNTAIN, which contained information on the Forerunner artifact found on Sigma Octanus IV. It also contained a full map of the CASTLE base facility on Reach that included a path to artifact, the Forerunner Crystal, beneath the surface of Reach.

Trivia
The letters CPOMZ are also an acromyn for: Chief Petty Officer Mendez (CPOMZ). Mendez was who trained the Spartans at a young age.