Hold - exclusive (Function + Hold)
An external call placed on exclusive hold can only be retrieved by
the extension that placed it on hold. Callers hear the system MOH source while they are on-hold. A system timer can be set to
revert exclusively held calls to system held calls after a defined time interval.
Hold - system (Hold)
An internal or external calls placed on system hold can be retrieved
by any extension. Callers hear the system MOH source while they are on-hold.