From Halopedia, the Halo wiki
The Career Service Vitae (or CSV for short) is a log kept on each soldier in the UNSC, similar to a civilian resume. Every member of the UNSC Armed Forces has one, as it keeps track of that person's entire military service. PERSCOM keeps track of the CSVs for all of the UNSC soldiers and archives them for public and military access.
Some of the things that a CSV contains include: