How did ransom "Used" to work?

So I was bored and since the ransoming mechanic seems to be (one of) the source of the OOS problems with the game, I decided to see if there was anything obvious ( i dont know shit about programming)

The only I can tell is that there is a DERansom tech which seems to be the current ransom tech in the game but it was kinda empty so I decided to look in legacy and I cant find any kind of ransom tech.

There is a ransom command but there is nothing that describes what happens. its not something hard coded into the game it is?