The Playboy Bunny outfit was the first service uniform registered with the United States Patent and Trademark Office (U.S. trademark registration number 0762884). The tight costume forced servers to bend at the knees, not the waist, when serving drinks; this maneuver became known as the "Bunny Dip". All drinks were served in the same glass, the long stemmed "Bolo Grande". A special round tray was developed with holes along the sides. The glasses stem would slip through and the bowl would sit flat on the tray. This allowed the Bunnies to carry drinks without spilling them and facilitated the dip.