The opposite of a "To-Do List", and isn't literally a list, but just an expression. Normally used when a friend/collleague/person says something that you should do/get and don't agree with. First appeared on the G4 TV Show "Code Monkeys".
Friend: "Hey, you should get that thing for that."
You: "I'm going to put that on my "To-Don't List"."
You: "I'm going to put that on my "To-Don't List"."
by Blinkovision July 28, 2011