One should always insist on the touch-move rule with every opponent in every (non-blitz) chess game whether serious or casual, rated or unrated. You will save yourself a lot of unnecessary vexation if you do. Now you might think you knew all there was to know about the touch-move rule; but if you are like me, you would have been wrong.
The rule no doubt applies to pieces on the board, but what about those off the board?
Suppose you have just promoted a pawn to the eighth rank. Some people wrongly refer to this as 'queening' a pawn thereby confusing the species with the genus. Promotion to queen is only one way to promote: there is also underpromotion to either a rook, bishop, or knight. There is no promotion to king since the 'dignity' of his majesty assures his uniqueness, and the 'ambition' of the pawn prevents his remaining in the lower orders.
Suppose you are in a position in which promotion to a knight will enforce immediate mate. But the time pressure is befuddling you and you reflexively grab a queen by the side of the board and replace the pawn with it. You do not, however, punch your clock. So technically, the move has not been completed.
Here is the question: Having touched the queen, and moved it onto the board, while leaving your clock running, may you change your mind and substitute a knight? Grandmaster Larry Evans, asked a similar question by Jude Acers, he of the red beret and the N.O. French Quarter, answers, "White must play 1 e8 = Q, since he touched the queen first, even if it was off the board." (Chess Life, November 2005, p. 45)
So here is a case in which touch-move applies to a piece that is OFF the board. Or at least that is the judgment of GM Evans.
The position described by Acers was one in which promotion to queen would have led to a draw, while promotion to a rook would have won.
Such are Caissa's charming subtleties.