Extremely minor oil leak near engine and transmission interface?

What is your question?

I think it is engine oil since it is brown, and not transmission fluid. Very minor leak right at the circular ring type area where the engine meets the transmission. I am assuming that this is not really a "wet" interface. So is the leak from the "rear engine seal" or the "crankshaft seal"? Do those seals mean one and the same thing? Or are there two different seals in that area?