Japan urges you to do it!
Japan's subways and trains are crowded, so transportation companies frequently hang posters to remind passengers to be considerate of others.
Recently, this series from Tokyo Metro has been running with different executions appearing each month.Apart from the numbingly clumsy and dull English copy (sadly, even today most Japanese companies can't be bothered to hire professional, native-English-speaking copywriters), the posters are eye-catching, and the copy does the job for the vast majority of passengers who are, obviously, Japanese.
