My youngest daughter is in Florence, Italy getting her Masters in Fashion Marketing/Merchandising. She complains that Italy is locked down so she's stuck in Florence. First world problem, huh? She was my designated photographer and I miss her! She was assigned a semester long project on US flight jackets. She actually had to go to a thrift store and get an old flight jacket (she picked up an MA-1) and had to take it apart and check out the construction. She knows I'm a leather jacket fan so she asked me a question I couldn't answer - and I can't seem to find the answer. Thought I may get some help here. How did the various jackets get their names? I assume A-2 is the next generation of the A-1, but why is it called the A-1. Why B-3, B-6, MA-1?