A true "Indy Air" is performed backside with the rear hand grabbing between the bindings on the toe edge while the rear leg is boned. The term "Indy" may also be used to simple describe the location of the grab.
A halfpipe aerial maneuver performed in the backside direction in which the rider's rear hand grabs the board between the bindings.
An aerial manoeuvre performed on the backside wall with the rear hand grabbing the board between the bindings. "Indy" also can be used to describe the location of the grab.