Lorraine Kelly offered baffled Line of Duty viewers some clarification after some misheard a word from Sunday's episode.
After a two year wait, fans were left beside themselves when series 6 of the hit crime drama kicked off on BBC1, after a gripping end to the last run.
Many fans took to Twitter during the episode to moan they were 'completely lost' by what was going on and something else many fans were left annoyed by was the use of crime jargon.
One particular abbreviation caused a big stir - CHIS - with some hitting rewind to try and work out what was being said, while others thought they'd heard another word entirely!
Addressing the CHIS shaped elephant in the room on her show on Monday, as a scene featuring new Line of Duty cast member Kelly McDonald played out on screen, Lorraine remarked: "Line of Duty returned last night but left a lot of people saying 'how do you locate your CHIS and some people misheard it and thought it was something else!
"CHIS stands for Covert Human Intelligence Source. So there! I had to look it up!"
Lorraine followed in the footsteps of a BBC announcer on the topic of CHIS, with the announcer revealing what it meant as the credits rolled on Sunday's episode, following a boat load of Twitter posts about it.
One confused viewer posted: "I totally misheard 'chis' I will let you work out what I thought I heard. I spent most of the programme trying to work out why they were using that word for an informant.
"Thought it must be something to do with spilling the beans"
Equally perplexed, another tweeted: "I really think the beeb needs to provide a glossary for Line of Duty. It could roll like credits at the start. Spent the whole programme in fierce debate over what CHIS meant.
"Also, beginning to wonder if they’re just making them up now!"
