That is, the dancers starting the call must ARM TURN (with 'any hand') to begin the call. Later during the call, 'push casts' are allowed when centers and ends interact, and 'partner trades' are allowed when centers need to turn 1/2.
Hence, the starting position should usually be an Inverted Box (one RH mini-wave + one LH mini-wave).
From a funny diamond (e.g., a RH diamond after one of the points u-turn back), you could call an Any Hand 1/4 Thru, which would end in a 3x1 Line.