Sounds like another ploy by the makers to sell yet another different type of net, I've been using the mono ones for a few years & still think that they are the best think since knotted nets were outlawed. they don't remove the slime from the fish, carp are much less likely to catch up their dorsals (which wouldn't happen anyway if people would only pull the bottom of the net through the upper rings to remove the fish instead of sliding the fish 12 or 14 feet thought the net & straight into the weigh pan. The mono landing nets are light as a feather & you can actually manouvre them around in the water with risking the net handle breaking and as an extra benefit they shake almost dry & don't stink the car out.
The net makers also seem to have got a lot of the Fishery owners on the side who are only allowing nets with the new mark on it. Bit of extra dosh for 'em I suppose, good little racket if you can say "can't fish here mate unless you buy one of my special nets - only 50% more expensive than in the tackle shops."
Unless the powers that be actually ban all but the newly marked nets I shall continue to use the mono nets that I already have. If the fishery owners don't like it I'll take my day ticket money elswhere.