Siemens 300Series User Manual page 122

To pick up a call
parked on a line
that appears on
your phone
5-12 ROLMphone 300/600 Series User Guide
Hang up.
The parked call will recall your extension.
When your phone rings, answer it and
begin speaking.
Press the line key with the flashing status
light.
Begin speaking. If you do not have a
speakerphone, you must pick up the
handset to speak to the other party.