LLF is an acronym for "Legally Licence Free" - It is used amongst citizens of the United Kingdom to describe someone who legally does not require a TV Licence which is used to funt the state broadcaster, the BBC.
George: Did you watch the football last night?
Dave: Nah mate, I can't watch TV as I've been LLF since 2017.
George: What on Earth is LLF?
Dave: Legally Licence Free. It means I've cancelled my TV licence and I'm sticking to the rules.
George: What if you didn't stick to the rules?
Dave: Then I'd just be Licence Free rather than Legally Licence Free.