Hi all. Firstly i appreciate theres probably posts on this very subject and believe me i have looked. Have found posts on people buying new but not upgrading. Anyway i have my nic domestic installer assessment due relatively soon. I have both red osg and regs book. Do i definately need to buy both new in green or are there ammendments to 1 or both of them? I was under the impression until recently you would only need to buy new after a totally new edition was published? Mo money, mo money!!!Cheers in advance and please could we keep the sarcasm to a bare minimum!! After recent open wallet surgery i could do without it all!!!