Originally referred to as the United Nations Intelligence Taskforce, executive producer Russell T Davies claimed in 2005 that the UN were no longer happy to be associated with the fictional organisation and the UN's full name could now no longer be used.However, the "UNIT" and "UN" abbreviations could be used as long as it was not explained what the letters stood for.
Other munitions include explosive rounds for Yetis, other armour-piercing rounds for robots, and gold-tipped rounds for use against the Cybermen (as well as silver bullets as suggested by the Doctor), In "The Christmas Invasion", UNIT is shown to have translation software which can decipher alien languages with great accuracy.
The software, or at least the results from the translation, can be loaded on a hand-held device.
In a 2014 interview with Doctor Who Magazine, script editor Terrance Dicks recalled that he was present at the "birth" of UNIT during the production of the Doctor Who serial The Invasion (1968).
He credited both scriptwriter and script editor Derrick Sherwin and producer Peter Bryant as having come up with the idea beforehand, claiming that they were testing the concept in The Invasion before it had become central to the show in the Doctor Who serial Spearhead from Space (1970).
From "The Power of Three" (2012), the first on screen appearance of UNIT in any Whoniverse media since the two-part Doctor Who special The End of Time in 2009–2010, UNIT has been shown to have been reorganised by Kate Stewart, the Brigadier's daughter.
UNIT personnel are seconded from the Royal Navy, British Army and Royal Air Force, and are still bound by the UK chain of command, and the commander reports to the Prime Minister and the Ministry of Defence through Department C-19.
There is also mention of them using helicopters and tanks while testing the destructibility of the cubes.
"The Day of the Doctor" (2013) shows that the Tower of London base contains the Black Archive housing various alien technological devices that UNIT has salvaged over the years and kept hidden away.
Sherwin was uncertain if the army forces featured in The Web of Fear appeared as UNIT, but was "convinced" that, as a teaser for UNIT's more substantial role in The Invasion, The Web of Fear was supposed to have replaced the basic army forces that were seen in the story.