I'm sorry that I offended you. I am absolutely in favour of keeping and using old threads, but when someone brings back an old post to either make some comment that has already been made, say something like I agree or things along those lines which clearly have no benefit to anyone reading the post later on, then it is a waste of time and I think that the term necro post would be appropriate in that instance. Basically I'm using the term in the context of reviving discussion for the sake of it and not for any perceivable educational benefit to anyone...