Thanks danger, I understand now. I have been wondering why the two gave such different results when they look so similar. I guess I'd better read the 5.6 docs again - I was assuming that the low precedence of not would make sure that the regex operation completed first - which as you have pointed out is true for versions prior to 5.6

Apologies to merlyn for saying that he was wrong, but I did test his example, and I did try to understand what was going on. I wasn't rude, so I am a bit upset at being --'d for my node.

I have learnt a lot in this node and merlyn's code, with danger's modification is going into the production system today.

Thanks monks.

-- iakobski