Panasonic KX-DT521 Quick Reference Manual page 9

Location of Controls
U EHS (Electronics Hook Switch) Jack *1
V FWD/DND *1
: Used to switch Call Forwarding or Do Not Disturb
on your extension.
W CANCEL *1
: Used to cancel the selected item.
*1 KX-DT543/KX-DT546 only
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