Heat Pumps and Electric Heating - Wire York Fossil Fuel kit to thermostat

I just installed a new gas furnace/ heat pump system in my home. I am a HVAC technician. This is the first time I have ever used a fossil fuel kit. I also do not have much experience with york/coleman. I got too good of a deal on this to pass it up, so I decided to put it in my own home. My main question is, my diagram shows to wire an X and a B terminal to the t stat. The b goes to the fossil fuel kit, then gos to the outside unit. The x also does the same thing. Now the B is common correct? So it would go to the "C" on a t stat instead of a B, right? Then what do I do with the X terminal? where would it go on a normal 2 heat 1 cool t stat?

What tstat, air handler and heat pump are we talking about? And where do those wire go?

We are going to need a make and model # on each items.