Vacuum lines to BOV?

[ppctx]

My BOV is similar to the one pictured below, having two vac nipples. I read that the top (horizontal) nipple is for a vac line sourced from within the throttle body. Read one post that said the lower (diagonal) nipple could be hooked up to some place prior to the TB plate, to aid something... what is that lower port for and I see there is a vac source just prior to the TB plate, is that where the lower one gets hooked to?

[WDRacing]

Yes...you nailed it.