What do OHCF white levers / switches on docucolor 242 oversize feeder

Sorry for being dense here as I'm guessing the answer should be obvious, but what do the two white levers do on the xerox 242's OHCF, or maybe I should say, how exactly am I supposed to use these two white switches? (the one on the front stop and the one on the adjustable side guide.)

 

i believe those are air adjustment switches, depending on the weight of the paper in the tray you are supposed to adjust them so the sheets are separating properly, we usually use these trays for heavy paper so we pretty much always leave them on the highest setting or at least that's what they look like from the pics

 

Thanks very much AllRush -- I'm still not seeing how these are connected to the air system... what I can see happening is that the one on the lead edge drops a small spring loaded white foot down located at the top of the register corner in the 1 position and lifts it in the 0 position. The switch on the side guide withdraws those two black feet and pushes out the silver "pads" or alternately withdraws the pads leaving two openings and pushes the feet, but I don't get when/how these come into play yet. I can't see how the two openings on the movable side guide have to do with the air unless it's really subtle as in where the air escapes... (or unless they're shared with another config of the same OHCF that has more air options...)

In my first 22,000 sheets I got 3 double feeds on lightweight stock / none on heavy from the OHCF which isn't terrible with no setting, but I think I can do better. Suppose I'll try moving to 0 for lightweight and see how that does next run.

(put the question into tech at the end of the day today and should get a callback on Monday too.)