Abstract: A multi-subscriber warning system can, in instances where emergencies are impending, apply ringing current to the "ring" lines of one party systems, to the "ring" lines of "ring" two party systems, and to the "tip" lines of "tip" two party systems. Those ringing signals will actuate the "ringers" of all instruments which are not in use, and will cause a buzzing sound in the reproducers of all instruments which are in use. Further, if a subscriber hears the "ringers" and raises the receiver from the cradle, a buzzing sound will be heard; and then the ringing sound will resume when the receiver is placed on the cradle. Conversely, if a buzzing sound is heard by a subscriber using the instrument, a ringing sound will be heard when the instrument is placed on the cradle; and the buzzing sound will resume when the receiver is again removed from the cradle. The duration and number of ringing sounds can be varied; and preferably will be different from the normal ringing sounds used to "call" a subscriber.