Uniform
The term uniform was used to refer to the clothing worn for the purpose of displaying membership in an organisation. During the Trojan War, Steven Taylor noted that, by taking a uniform, he would be captured as a prisoner of war instead of a spy. (TV: The Myth Makers)
Bus drivers wore uniforms. In the early 21st century, the Ninth Doctor wore one while hijacking the 68 to Bolton. (PROSE: Have You Seen This Man?)
Police officers wore uniforms. By 2018, English police uniforms included uniform cameras. (TV: The Tsuranga Conundrum)
At school, school uniforms were worn by students. (TV: The Curse of Clyde Langer)
Gwen Cooper reported to her fellow Cardiff police officer Andy Davidson of a man in a porter's uniform being attacked by a man wearing a mask. (TV: Everything Changes)
The Moroks were distinguished from the Xerons by their uniforms. (TV: The Space Museum)
The US naval uniform was worn by members of the United States Navy. (TV: Praxeus)
During the 2000s, red caps constituted part of the uniform of UNIT soldiers. (TV: The Sontaran Stratagem/The Poison Sky) Reuniting with his old friend Martha Jones, now a member of UNIT, Jack Harkness jokingly asked if she could provide him with a red cap, suggesting that Ianto Jones would look good in one. Martha told Jack to get his own uniform. (TV: Reset)
While working for Torchwood Three, (TV: Children of Earth: Day Four et al.) Captain Jack Harkness wore what Owen Harper described as a "military uniform." (TV: Fragments) His attire would earn him the nickname "World War II" from Rex Matheson. (TV: Rendition et al.) He did not always wear it in full though, something Bilis Manger noted when encountering Jack in 1940s war-time Britain. Jack, having came there by accident, lied that he was on leave for 48 hours. (TV: Captain Jack Harkness)
In a parallel universe, uniforms were worn by individuals serving in the Starfleet of the United Federation of Planets. (COMIC: Assimilation)