consider that the term "Easter egg" for hidden surprises in software, put there for people to find, was still years away in 1973, but the practice of hiding Easter eggs was very much alive, and in fact goes back to the beginning (unfortunately some Easter eggs were just excuses to be nasty)
unfortunately, TREK73 (1973), an early (unofficial, fan-made) 'Star Trek' game for mainframe computer at the start you were asked to specify sex; if you typed 'M' you would be addressed "SIR", if you typed 'F' you would be addressed "MISS", you could give any other character and get a random slur