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Full list of Line Of Duty acronyms explained - from CHIS to PNC

25 March 2021, 11:39 | Updated: 25 March 2021, 11:41

Line of Duty is back on BBC, but viewers are confused. Picture: BBC

By Naomi Bartram

What do MIT, AC, PNC and TA mean in Line of Duty? Your complete guide to police acronyms...

Line of Duty is finally back on BBC One, with crime fighting trio Superintendent Ted Hastings, DI Kate Fleming and DS Steve Arnott taking on a new case.

But while we we're all very excited to see AC-12 again, there are a few moments which continue to leave viewers scratching their heads.

Mainly at the mention of CHIS, PNC and MIT...

So, as we sit down to watch another episode of the BBC crime drama, let’s take a look at all the acronyms we’ve learnt so far.

Line of Duty season 6 is airing on BBC. Picture: BBC

Line of Duty acronyms

CHIS - Covert Human Intelligence Source
MIT - Murder Investigation Team
PNC - Police National Computer
TA - Tactical Advisor
AC-12 – Anti-Corruption Unit 12
ARU - Armed Response Unit
ARV - Armed Response Vehicle
AFO - Authorised Firearms Officer
TFC - Tactical Firearms Commander
AM - Active Message
Sit Rep - Situation Report
SIO - Senior Investigating Officer
DIR - Digital Interview Recorder
UCO - Undercover Officer.
B&E - Breaking and entering
CID - Criminal Investigation Department
CIS - Crime Information System
CPS - Crown Prosecution Service
MIT - Major incident team
NCS - National Crime Squad
Fahrenheit - AC-12's codeword for 'shoot to kill' - this is different for each police operation.

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Police rankings

DC - Detective Constable (cops who have passed their detective exams get a “D” instead of “P” before their rank)
DS - Detective Sergeant
DI - Detective Inspector
DCI - Detective Chief Inspector
Det Supt - Detective Superintendent
DCS - Detective Chief Superintendent
ACC - Assistant Chief Constable
DCC - Detective Chief Constable
CC - Chief Constable

If you can’t remember all those, then don’t worry because even newcomer Kelly Macdonald, who plays DCI Jo Davidson, revealed she struggled at the start.

She explained: “There would be certain acronyms that we would discuss at the time.

“In hair and makeup, they had a list pinned up, which was quite helpful, I found, of all the acronyms and what everything stood for. I’m not brilliant at [remembering them], but I sort of get by.”

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