Sharp FO-90 Operation Manual page 15

Connections
Connecting the Handset
Connect the handset as shown and place it on the handset rest.
♦ The ends of the handset cord are identical, so they will go into
either socket.
Make sure the handset cord
goes into the socket marked
with a handset symbol on
the side of the machine!
14
Use the handset to
make ordinary phone
calls, or to transmit and
receive faxes manually.