Panasonic KX-T336 System Reference Manual page 331

FWD/DND Button
This button can be used for setting or canceling the Call Forwarding or Do Not
Disturb feature.
CONF Button and Indicator
Allows the user to perform a three party conference.
FLASH Button
This button causes a flash signal to be sent' to the Central Office.
MFSSAGF mton and Indicabx
This button can be used for Message Waiting feature.
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