I just noticed that on PIf5 on Table PIf5-1 the second part refers to a main corridor and the third part refers to a secondary lobby/corridors. What does this mean?

Our project is an speculative office building, with a main lobby.

Is main corridor the one that takes you from the lobby towards the elevators? and, Are secondary corridors all the ones that takes you from the elevator lobby (levels 2, 3, 4, 5, etc) to the leasable space?

Thanks!!