本《美国国家电信标准——消息等待指示器和通知补充服务及相关交换和信令规范》（ATIS-1000622.1999（R2008））的补充修订了本标准，以改进和扩展本标准的适用性，尤其是在与NT2接口时。以前称为T1。622a-1998（R2008）。

This supplement to American National Standard for Telecommunications - Message Waiting Indicator and Notification Supplementary Services and Associated Switching and Signaling Specifications, ATIS-1000622.1999(R2008), revises the standard to improve and expand the applicability of this standard, in particular, when interfacing to an NT2. Formerly known as T1.622a-1998(R2008).