A History of Short Words

From the New York Times Crossword Puzzle

PTAS

Fri, 8 Oct '21
Grps. receiving Our Children magazine
Tue, 10 Aug '21
K-12 fund-raising grps.
Sat, 7 Aug '21
Groups involved in class actions, for short?
Sat, 31 Jul '21
Readathon supporters, for short
Fri, 4 Jun '21
Certain fund-raising orgs.