Sony GRAND WEGA KF-60DX100 Operating Instruction page 74

Using the Menus
r
8 Move the joystick left or right to select the extender to be viewed, and
h
press @J.
"-" appears beside the selected extender, indicating that the programs
that match the extender can be viewed.
If you press @ again, B is displayed to show that the programs that
match the extender will be blocked again.
1
9 Repeat step 8 for other extenders.
All programs that match the ratings you select an&higher, except for the
extenders that were canceled, will be blocked.
"
10
Press
MENU
to exit the menu screen.