Comet tail light question

What is the function of the inside pair of Comet tail lights? Are these only back-up lights? Do they do anything else, brakes, etc. Do they use single or double pole sockets? What does the wiring diagram look like? All I have is wiring diagrams for Maverick.

 

I remember mine only worked as reverse.

 

Back up lights only and they use a single pole 1156 bulb. Wiring would be the same as the Maverick.

 

My '72 uses dual contact, single filament #1076...

Or at least did, I modified the back up lamp sockets from a '88 T-Bird to fit the Comet housing, those use a 1176...

 

They are reverse lights and reflectors