Comment 4 for bug 368107

The || button is a "Hold" button, not a "Mute" button. If the server is configured to do so, putting the call on hold will play hold music, where mute will just disable your microphone.

I often join conference calls where I mainly listen, but sometimes speak. In these cases, I cannot put the call on hold, otherwise the other members of the conference will hear hold music. I just want to be able to quickly mute/unmute my microphone, and to easily see if I'm on mute or not.