Taskmaster

I was wondering if it was something like the first word of every task they did, but then I remembered they don't do them in the same order (and some don't get shown to us at all). So perhaps it is just a secret envelope somewhere in the house (like behind the Metropolis Greg painting).

I would not put it past them to be pulling the legs of all the contestants with the secret task.

They were only mentioning it when the contestants were in front of the Greg artwork until this week when it was mentioned in the lab. Until then I was wondering if it was something in plain sign within that room, perhaps stuck to the wall with the wax seal painted white.