Trane Programmable Thermostat What Is The "T" Wire For On A Thermostat?

What is the "T" wire for on a thermostat? - trane programmable thermostat

I bought a programmable thermostat to replace my old Trane, Honeywell thermostat. I have a heat pump with auxiliary mode. The installation is quite simple, as stated in the manual, but then I am using a cable that was connected to a "T" screws and is now shared on the left. I have set two possible places to either "L" or "RC", or I could just as easily with adhesive tape, if something good. Ultimately, the key is knowing what you are doing. Of course, I have tried to support Honeywell, but they are closed today and I like to get this project finished and I'm so close to being done. Any help would be appreciated.