are: used in emails and text messages （用于电子邮件和手机短信中）
RU free 2nite (=Are you free tonight?) 你今晚有空吗？
2
AMERICAN restricted: used in the US for saying that people under the age of 17 cannot go to a particular film unless they go with an adult （影片）限制级的（指美国17岁以下青少年须成人陪同方可观看的电影）