Siemens Hicom 150 optiset E standard User Manual page 21

Should you fail to answer a Call Back that you have activated, the system will
automatically cancel the feature after ringing your extension for a predetermined
time.
Cancel Call Back
- scroll to display callback? option
- press
CALLBACK: mr jones
- scroll to delete callback? option
- press
or
Cancel All Call Backs
- lift handset, listen for internal dial tone
- dial # 77
Call Back - Cont'd
key to confirm display callback? option
key to confirm delete callback? option
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