The pannenkoek2012 Wikia

A unique A press refers to a single circumstance under which the A button must be pressed during a run. This circumstance may occur multiple times, leading to multiple A presses; if a workaround is found for the unique A press, all of those individual A presses may be saved.

For example, if entering a course requires an A press, the case of entering the course is a unique A press, even if the said course must be visited multiple times over the course of a run.

Below is a table of unique A presses in the A Button Challenge.

A Press # Stage Purpose Multiplier
#1 PSS ! Block Star: To collect the ! block star 1
#2 SSL Inside the Ancient Pyramid, Pyramid Puzzle: To jump out of the elevator. 2
#3 BitFS Go to Bowser: To jump off of the pole. (saved in Wii VC only) 1
#4 THI Wiggler's Red Coins: To jump to the blue coins platform. 1
#5 THI Wiggler's Red Coins: To jump to the high platform above the red coin star platform. 1
#6 Castle Enter TTC: To Enter TTC 3
#7 Castle Go to RR: To go to RR. 1
#8 Castle Go to WMotR: To go to WMotR. 1
#9 WMotR Red Coins: To launch from the first cannon. 1
#10 WMotR Red Coins: To launch from the second cannon. 1

Source: https://docs.google.com/spreadsheets/d/1wVD60DYcPPjWmfObqwV-1Kb0ic478dsL9znCMqM2X4M/edit