Portal assignments

I posted this in an old post, so I thought maybe if I created a new one, I'd have better luck: I understand the recommendation is to use TR_SECTION and the additional text to assign portals. If there are 3 areas in a section, left, center and right and two portals, between left/center and right/center. Then if someone sits in the center section, how would I know which of the two portals to list in the additional text area. There would need to be a specific way of saying this portal is to be used for people seated ORCH CTR 101-115, as an example. How do you handle situations like that? Unfortunately I think maybe I would have had to created additional sections for ORCH CTR LFT and ORCH CTR RGHT. I just have one for orchestra center. Cheers, Holton