Why does this Holley 2280 have a "port" directly into the venturi?

TylerW said
Speaking of PORTED vacuum signals, what is the significance of slots that are horizontal directly above the throttle blade and those that are slightly vertical and slightly farther away(upward) from the throttle blade?

Thanks...

Those are transition slots to cover when you go from the idle system to the main system.... For a smooth transition...