The .7z extension indicates that the file was created using , a free and open-source file archiver. 2021 USAF & USSF Almanac: Specialty Codes
The is an alphanumeric string used by the U.S. Air Force to identify specific job roles and career fields. afsc.7z
Understanding afsc.7z: Data Archiving for Air Force Specialty Codes afsc.7z