For anyone who doesn't recognize it this looks like pretty standard Gottlieb Score Motor nomenclature. Compare it to this for example:
Gottlieb Score Motor (resized).jpg
The chart was redrawn but has essentially the same information. The diagram is just rotated 90 degrees.
The values in the table indicate how many switches there are of each type: A: normally open, B: normally closed, C: Make/Break.
On Gottlieb motors switches mounted in the 1A and 4A positions typically activate five times per 120 degrees while all the other switches activate just once.
/Mark
