The antonym of "naff" is "bona", but how are our poor friends in the US going to know about Polari if they are not also told that it is local to central London? I'm only commenting because "Naf Naf" is a French designer label which chic shops all over France and London have plastered across their windows - always makes me laugh, as does a curio shop in Boulogne which is named, in letters a foot high, "Les Mysteres de Fanny"