Regulations for Passenger Ship Administration Article 53

Each space of the passenger cabin shall be marked with the use, class and number on the front of the door. Markings shall be made in characters or signs when cabins are separated for men’s and women’s use.
中文原文 客船管理規則第53條
乘客艙室應於各室門前,標明其用途、等級及編號。
男女乘客分別專用時,應用文字或標誌表示之。

English translation for reference only; the Chinese text prevails. Not legal advice.