what means RIB, LOB etc...concerning machineguns position in plane

[Flyingkag]

Hey

on many MACRs we can read the serials of the machinguns used in plane, and their relative positions in plane.

I can read on the ones I have: LIB, LOB, LOB, RIB, ROB, ROB

I believe :

L and R are for Left and Right, ok?
I and O should be for "inside " and "outside" of the wing; no reference to the "middle "one machinegune in such a list

so, I have two questions:

Concerning what is the "right side", is it the one on the right side of the sitting and shooting pilot, or the one of an armorer staying in front of the plane and looking at it?

I guess the machingun in center of each gun bay in each wing is the one in the middle of 3 left/right in this kind of lists?

Thanks for any help, Mathias