Whether you have been a fan from the very beginning or just joined this series, there is no mistaking that Line Of Duty has truly gripped TV viewers for the last six weeks.
Now is probably a good time to declare SPOILER ALERT but if you're still not caught up on the epic drama, where have you been?
As the fifth installment of the BBC police drama reaches a dramatic climax in a mammoth 90-minute long finale on Sunday, May 6, we have many questions left to be answered.
Is Superintendent Ted Hastings really bent? Will he be sent to prison? Is he being framed?
But the most important question of all, who is 'H'?
As the series wraps up, we are expecting some big interview scenes.
So we thought that it was important you were up to scratch with the all confusing police lingo.
From OCG to UCO, you'll need to have all these at the ready if you're really want to understand the action:
AC-12: Anti-corruption unit 12
ACC: Assistant chief constable
AFO: Authorised firearms officer
ANPR : Automatic Number Plate Recognition
ARVs: Armed Response Vehicles
CHIS: Covert Human Intelligence Source
COM: Covert operations manager
DI: Detective Inspector
DIR: Digital Interview Recording
FI: Forensic Investigator
I.P. Address: Internet Protocol address
IOPC: Independent Officer for Police Conduct
I.R: Incident Report
MOPI: Management of police information
OCG : Organised Crime Group
PACE : Police and Criminal Evidence Act
REG 15 : Regulation 15 notice of misconduct/gross misconduct
RIPA : Regulation of Investigatory Powers Act 2000
RTC: Road Traffic Collision
SFC: Strategic Firearms Commander
UCO: Undercover Operative
VO: Visiting Order
VPN: Virtual Private Network
