DuckCorp Dico

Found one definition

1.                 From The Free On-line Dictionary of Computing (19 January 2023):
                   
   
   
                   
                     
   April Fool's Joke
   AFJ
      <humour, event> (AFJ) Elaborate April Fool's hoaxes are a
      long-established tradition on Usenet and Internet; see
      kremvax for an example.  In fact, April Fool's Day is the
      *only* seasonal holiday marked by customary observances on the
      hacker networks.
      (1995-01-25)