Oh, thanks for the explanations, I thought I was going mad! I've been on here for more than 3 years and know of a few posters who have had their whole posting history withdrawn (and are still here under a nc) but hadn't realised that you could ask MNHQ to change your posting name retrospectively instead. Not sure why I'm seeing lots of these threads now, probably because lots of zombie threads are being resurrected for some reason!
Have just realised that my second post here totally outs the poster who nc'd and undermines the whole purpose if the exercise . Will report it so MN can delete if they want!
A couple of times in the past when a poster has been outed HQ have changed their names retroactively, so as to protect them from advance seaches and avoid deleting reams if posts which leave threads disjointed.
They don't like to do this as it gets confusing for newer posters so is very rare.
I keep reading old threads that have been bumped a couple of years later and finding that some of the posters are being addressed by names that they're not using on that thread - as if everyone else on the thread can see that they've got a different name .
I realise that sometimes people nc but everyone knows who they were before and addresses them by the old name, but I don't think that's the case here. It's making me a bit paranoid that ncs can display differently retrospectively .