How do you identify drivetrain hardware?

In other words, how do I identify an ACD Transfer Case vs a standard Viscous Transfer case?

Same with the transmission, how do I identify an LSD equipped tranny vs a tranny with an open diff?

Is there some sort of ID code or model number on the unit?

 

There should be an id tag on it.

 

And I'm assuming that the ID tag can be viewed with the parts mounted or already installed?!?!