It is a CDC (Career Development Course) book for upgrading avionics specialists. The career field is broken down in to 3 shops - A, B & C shop. A-shop is "Attack Control Specialist". B-shop is "Flight Controls & Instrumentation". C-shop is "Communication & Penetration Aids". That is how F-16 maintainers break down, the Eagle maintainers are very similar, maybe some differences in career field titles, but all the same in the end.
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