Uniform

The term uniform was used to refer to the clothing worn for the purpose of displaying membership in an organization. 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)

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) Billis noted how Jack was "not in uniform" when encountering him in 1940s war-time Britain, with Jack using the excuse that he was on leave for 48 hours. (TV: Captain Jack Harkness)