Dropped Infield Fly

[Centerfield9]

ASA. Cannot find anything in the rulebook about this.

Are the runners required to tag their base on a dropped IFF? One side of the discussion says the rules of a caught flyball apply whether or not the ball is actually caught on an IFF, so all runners must tag up (BR is out either way). The other side says the BR is out, but the rules for a caught flyball apply if the ball is caught, meaning the runners must tag up, and the rules for a dropped flyball apply if the ball is dropped. The force is off, of course, but if the runners are off the base when the flyball contacts the fielder's glove, the runners can immediately proceed to the next base without tagging up.

Referencing the rule number would be helpful.