Come to think, I purchased the truck off the lot with no keyless entry. I negotiated a dealer installed one in the deal. Come to find out the dealer installed remote entry was actually installed by some specialty electronics place down the road. I think this explains what it is.
I couldn't for the life of me figure out why I didn't see this when I installed my brake controller. Then I remembered that I installed the brake controller before the remote keyless entry went on! Now I feel pretty darn stupid!