What are FAA Part 121 "supplemental" operations?

Question

Also, can you tell me where you found your answer. I tried looking it up in the FAR's online. I found numerous references to supplemental operations but nowhere was there a definition of what they were. Even in the FAR Part 1 definitions, supplemental operations were not mentioned. Is this one of the things that the FAA just expects one to "know" (through osmosis maybe)? Very frustrating (but typical of a governement organization, I guess).

Answer 1

14CFR119.3