ff, you can't flounce. You haven't done the paperwork.
1 first you have to start a pointless thread that gets everyone riled up and at each other's throats.
2 next you tell everyone to stop posting on that thread.
3 email mumsnet and ask for the thread to be deleted.
4 post how annoyed you are that they've decided not to delete the thread.
5 msn all your friends to get them to tell everyone you're flouncing and start threads begging you to stay.
6 Do not post on said threads but sit and read them feeling smug.
7 If anyone posts that they don't care whether you come back or not, send them emails full of insults and slander.
8 Now you can flounce and start thinking of a new name to start posting with tomorrow.
It's as simple as abc.