GT, the proper term would be “supine grip bench press”. “Supine bench press” just means lying supine when executing a bench press, so that term really applies to all bench pressing. The supine grip bench press places more stress on the triceps and less on the pecs than regular bench because of the orientation of the upper arm; the pecs are internal rotators and horizontal adductors, so externally rotating the upper arm and bringing the elbows in close to the body (as one does in the supine grip bench) inhibits the pecs from firing. It can be a decent exercise if it doesn’t bother your wrists or shoulders, but I find close grip benches to be much more comfortable.