Nope, what is it? Nothing shows up in my Google searches other than plain old "false cards", which are fairly obvious. I don't remember bothering to name such a thing.
Declarer leads the A, parter plays low, dummy plays low. Do you discard the Q or the T?
Since you have to discard a non-small card declarer will know you have either a singleton, or QT doubleton, because with any other holding you'd play something else. If you have T singleton, there is nothing declarer can do about it except lead small to dummy's J at trick 2. However, if you can convince declarer you have Q singleton, the right play is to hook the 9 in dummy. Thus, playing the Q at trick 1 is a mandatory false card - discarding the ten will never gain, discarding the Q puts declarer on a genuine guess.
At very high levels, this gets further randomized because declarer will pickup on the Q likely being a MFC, and thus work to otherwise resolve the guess and get it right (e.g. play other suits and using deductive reasoning from that. - so at very high levels the winning strategy is actually to make the MFC most - but NOT ALL - the time, at random.
On the other hand, for the declarer it is just business as usual: you try to navigate the tricks making as few guesses as possible. At some point realize that seeing the Queen doesn't always mean a singleton, so you put that in the "guess" category, but the actual process isn't effected.