订阅者是请求创建订阅的实体，它发送一条Subscribe Request Message到通知代理。

A subscriber is an entity that requests the creation of a subscription. It sends a subscribe request Message to a notification broker.

youdao

立即通知他，他得于明天下午之前到市政厅来。

Get word to him right away that he's to present himself at City Hall by tomorrow afternoon.

《柯林斯英汉双解大词典》

全体学生获通知到大礼堂集合。

All the students were asked to assemble in the main hall.

《牛津词典》