Zero,
The memo is a BAA memo (available in the crewroom). The reference is BAA DN/44/10 and it sets out the requirements for crew taking hold baggage airside. I keep the reference in the notes on my phone for just such an occasion!
BTW I think the rule is that you have to go through Enterprise House if you have hold baggage so that is why you may have problems at VP9. I've never had any issues at Enterprise House - although I did see a guy once getting told he couldn't take his bag through. Then again, it was a fully loaded huge Samsonite case.