In plain terms. DAFFARS is the Department of the Air Force's acquisition supplement, adding Air Force-specific guidance on top of the FAR and DFARS.
Who it applies to. Contractors selling to the U.S. Air Force (and Space Force).
What it requires. Comply with the FAR and DFARS, then Air Force additions in DAFFARS. Because the work is Department of Defense work, contracts here generally carry the core DFARS cyber clause 252.204-7012 — protect covered defense information to NIST SP 800-171 and report cyber incidents to DoD within 72 hours — plus CMMC requirements as they phase in.
Why it matters. The Air Force layer handles departmental procedure; the binding cyber requirements flow from the DFARS clauses in your contract.
Citation. DAFFARS, the Department of the Air Force FAR Supplement supplement to the Federal Acquisition Regulation (FAR), codified in the FAR System at Title 48 of the C.F.R.