带外发信 out of band signaling; out-of-band signaling; out-of-band signalling
信件 letter; mail; missive 打印信件 a form letter; 商业信件 business letter; 发出的信件 an outgoing letter; 友好的信件 a friendly letter; 他每天有大量的信件要回复。 he has a large amount of mail to answer every day
发信 1.(发送信件) post a letter; send2.(发送信号) transmitting
Review the need for the preparation of periodical reports , the distribution lists of outgoing correspondence and hard copies required for circulation 检讨是否有需要定期发出报告复核外发信件的分送名单检查传阅文件应否以纸张印本形式传阅。