Terminal 1, 4, and 15 on the coil Options

[turnaround89]

So im taking my car back to fuel injection and im going to bypass the relay board. Ive been looking in my haynes manual at the wiring diagram and the coil shows three terminals. My newest coil has a + and - sign on it with double post terminals. What ive gathered so far and just want to make sure im close or maybe correct in reading the diagram.

Terminal 1 would be the (-) side of the coil because the tach signal wire comes off that post(blk/purple wire) as well as a green wire that goes to the distributor which i think would be the condenser wire.

Off of terminal 4 comes a black wire that also goes to the distributor. What wire is this and where does it attach to the distributor?

Lastly, where is terminal 15 on the coil? The diagram points to the back of the coil, but there isn't anything there. May be a stupid question but i have no idea what terminal 15 is

A little info, my car has been completely rewired by myself not using a stock wiring harness. I wired up the ignition using the simple ignition circuit shown by lapuwali. Here is how my ignition circuit is wired up, the starter switch in the picture, is actually a relay.