Agree totally Woody. Thats my definition too. When they are silvery and you can skim them over the surface because they are not much thicker than razor blades you have a 'skimmer'.
Afraid they are my least favourite fish to catch. Nothing really to commend them, no fight, not in any way beautiful like a rudd or crucian, and they peck away at paste intended for carp and tench!
Bob Nudd is welcome to them.