WAAF

Set to 2 different clues across 2 published puzzles, most often “W.W. II Brit. group” — The New York Times, Sunday, 22 September 1996.

4 letters

Every clue on record, most used first

W.W. II Brit. grouponce
The New York Times — Sunday, 22 September 1996
Women's auxiliary of 60 Down: Abbr.once
The New York Times — Sunday, 2 January 1994