Sony KP-51WS510; KP-57WS510; KP-65WS510 Service Manual page 244

Using the Menus
68
8
Move the joystick left or right to select the extender to be viewed, and
press .
"-" appears beside the selected extender, indicating that the programs
that match the extender can be viewed.
If you press again,
match the extender will be blocked again.
9
Repeat step 8 for other extenders.
All programs that match the ratings you select and higher, except for the
extenders that were canceled, will be blocked.
10
Press to exit the menu screen.
MENU
is displayed to show that the programs that