On Aug 14, 11:54*pm, "Tim W" wrote:
Last time I used it the principle difference was that the edge was tapered,
on one side only. This was to accommodate the nasty european habit of taping
the join, filling the taper but not skimming the whole face, just painting
or papering onto the plasterboard.

I was taught this as the preferred approach on a DIY plastering course
in Britain recently too.