I think it might be "N.AF" or "N.AFo" or N.AFr" meaning "Now (in the ) Air Force". Both of the men Rodreick and Zukowski went on to serve in the Air Force (which became a separate service in 1947). Rodreick retired in 1960 and Zukowski served in both Korea and Viet Nam.
For those without Fold3 access, here is a description of what is on the MACR page.
The notation appears to relate to a column headed "Current Status". All of the nine men (three officers and six enlisted men) originally had MIA (typed) in that column. All of the men have the notation RTD (Returned to Duty) hand written in the right margin of the page. Then for five of the nine men listed, someone, at some point went back and wrote "N.AF" in front of the MIA for the pilot and co-pilot and for three of the enlisted men actually crossed out MIA and wrote in RMC (Returned to Military Control) in front of the crossed out MIA.
Zukowski's grave:
https://www.findagrave.com/memorial/...thony-zukowski