You can hold one or more calls.
The held call still occupies the appearance button on which it was made or answered. A fast flashing green lamp is used to indicate held calls.
The caller hears music on hold. If your system does not have music on hold available, the caller hear double beep tones every few seconds.
If you have more than one held call, or one held call and a connected call, pressing the Conf soft key starts a conference between yourself and the calls.