The Administrative Regulations on the Ship Radio Station Article 15
When distress traffic has ceased on a frequency which has been used for distress traffic, or complete silence is no longer necessary for a frequency which is being used for the traffic, the ship radio station for controlling the traffic shall transmit on that frequency a message addressed to all radio stations, indicating that normal working may be resumed .
中文原文 船舶無線電臺管理辦法第15條
遇險之船舶無線電臺或管制遇險業務之電臺，當遇險業務已告終止，或作為遇險業務之頻率已無靜默之必要時，應在該頻率上發送對所有電臺之通信，告知正常工作得以恢復。