

That's the trouble with rules, they tend not to fix things, just create rule breakers and create an ever increasing complexity of defining and and interpreting.
I think Glenny's suggestion of having judging panels is a very good suggestion. After all we have judging panels in the performance comps and in those performance comps, both the participants and the performance pieces are often recycled and well known before hand.
They don't need rules about previous exposure. Do they ?
Long live the antinomian revolution.
