and yep, the edit option disappears after a while.
not helpful 
I think it's very helpful - and not just because it stops posters spitting out their dummy.
I noticed on Pepipoo that some posters would edit their posts after somebody had subsequently pointed out that they'd been "mistaken" about something they'd posted. It was quite obvious that the person who'd been mistaken then retrospectively edited their original post so that the "mistake" was removed - but they didn't indicate that they'd edited the original post.
It was obvious because the person drawing attention to the mistake had quoted the original mistaken post.
I think it's not on to go back to correct posts that you've got wrong without indicating that you're correcting a mistake - it ruins the continuity and integrity of the thread otherwise. If I'm going back to correct something I've got wrong I'll make it clear what I'm doing. eg
[Edit: I've corrected this because user xxyyzz has subsequently pointed out I was wrong]I also try to make it a rule not to edit a post if somebody has posted afterwards because it can make their responses look meaningless. If I do do that, I make it perfectly clear what I'm doing and why: eg
[Edit: I've corrected this because later posts have shown I'm wrong]I try not to edit anything except in the heat of the moment - ie I've just posted something and realised there's a typo or something.
