Daily D. Dave -
"Firstly I've never heard that in my life and I'm guessing I fly in the UK far more than you do."
That's the first you've heard "Climb Level 400"? Pronounced 'four hundred'. Isn't that the standard call and correct RT? I'm feeling stupid right now because I've heard it numerous times and didn't realize it wasn't 'approved' RT. What is the correct RT?