where the starfleet arrow was just an outline surrounded by two gold vertical bars. This badge was also worn by Geordi La Forge in the Star Trek: Voyager episode "Timeless" but on the gray shoulder uniform used in the last three TNG movies and the later episodes of Deep Space Nine. The Star Trek: The Next Generation episode "Parallels" used an alternate combadge design where rank was denoted by the number of bars behind the arrowhead. Variations in uniforms and insignia are occasionally used as plot devices in the various series. In the episode "Future Imperfect", the insignia are slightly altered so as to convince a character that 16 years have passed. In the episode, "Parallels", variations in uniforms and insignia suggest a meeting of characters from different parallel universes. Prequel era Star Trek: Enterprise In Enterprise, field officers and crewmembers wear duty uniforms consisting of a dark long-sleeved undershirt and blue jumpsuit with colored piping around the shoulders and, occasionally, baseball caps. There is also a desert uniform with khaki pants and white shirt. Both uniforms have a United Earth Starfleet patch (featuring the stylized arrowhead emblem) on the right upper arm, and a patch left upper arm denoting the ship one is serving on. Enterprise, set before all other incarnations, did not include characters who hold the ranks of lieutenant commander or lieutenant, junior grade. The highest-ranking admiral seen wears two sets of three-pip insignia. Division colors follow the original TOS scheme, with command and flight control officers wearing gold piping, engineering, communications, and security officers wearing red piping, and medical and science officers (including linguists) wearing blue piping. Throughout the series, men and women wear the same type of uniform. Unlike the other series' uniforms, standard uniforms on Enterprise include zip-up pockets, and the undershirt is buttoned at the neck - while Gene Roddenberry had explicitly forbidden such devices as buttons and zippers on Starfleet uniforms, believing they would be obsolete in the future, designer Bob Blackman consciously used them as a way of dating the series, implying that closures Roddenberry envisioned had not been invented yet. Blackman described the jumpsuits as "more like a NASA flight suit" than the previous Starfleet costumes, and actors from other Star Trek shows envied the Enterprise actors' much more comfortable and conventional outfits. Admirals wear a navy-blue jumpsuit-like uniform, open to show a white shirt and navy tie. The jacket