Siemens HICOM 300 - Manual (Page 21)

21
Override a call on a busy extension
NB. Override is not possible if the extension is in the process of dialling or in
an extension controlled conference.
What you have to do What happens
You have extended a call and found it busy.
Depress You are connected to caller
You advise caller extension is busy
and now wish to override.
Depress The extension will hear override
tone.
Advise extension of waiting call.
Both extension and the party to whom
the extension is speaking will hear you
override and advise of waiting call.
To extend call
Depress Caller camped-on to busy
extension.