Regulations Governing The Approval and Administration of Direct Cross-Strait Sea Transport Between the Taiwan Area and the Mainland Area Article 9
The vessels registered in the Mainland Area shall not fly their flag on the stern and mainmast of the vessel between entering and leaving the direct transport ports in the Taiwan Area, but shall fly their company flag for vessel identification.
中文原文 臺灣地區與大陸地區海運直航許可管理辦法第9條
大陸地區船舶入出臺灣地區直航港口期間，船舶懸掛公司旗，船艉及主桅不掛旗。