Thanks all, especially 747FOCAL. Managed to get to the office and dig out the relevant bits in due time.
Yes, searching is a great idea, but here, the search title has to be greater than three characters long, so entering V2 is not possible. I did mean derivations, by the way! Thanks nonetheless for the info. Good reading.
m&v, I did, then leant it to 'a friend'...
cumulus, just take a reality check on the old 'Do I need to get a life?' question once in a while!!
Happy landings all!
CP