Japanese politeness and reserve is taken to a new level in this NO SMOKING sign which has the rider narubeku (なるべく, "if at all possible") attached. It's a very subtle way to appeal to the reasonableness of smokers to refrain from lighting up, something that is much more effective than admonishing in that often snooty tone, "Go-enryo onegaishimasu" (ご遠慮願います, "You are requested to refrain from . . . ").