Panasonic KX-FP373FX Operating Instructions Manual page 41

Feature
Resetting advanced
features to their default
settings
Feature code Selection
{0} "NO" (default)
{#}{8}{0}
{1} "YES"
To reset the advanced features:
1. {MENU} i {#}{8}{0}
2. Press {1} to select "YES". i {SET} i {SET} i
{MENU}
Note:
L The ECM selection (feature #68 on page 39) will not be reset.
7. Programmable Features
41