On the top row of the 536 you will see "F_:__________".
Some translation is needed.
The character beside the "F" represents the first digit of the Favorites List Quick Key number. Those characters after the ":" are the second digits for the Favorites List Quick Key Number.
When you see numbers, that means the FLQK is active. Asterisks "*" mean the FLQK is turned off and dashes "-" means the FLQK is unassigned.
So if you have only two Favorites Lists that are active, with a FLQKs of 1 and 2, you'll see "F0:12-------". If FLQK is turned off, you would see "F0:1*-------".
For FLQKs higher than 9, such as 10, you should see "F1:0--------". With that said, you will not see numbers higher than 9 displayed if the FLQK is off or the Favorites List is Avoided for some reason such as Avoid is on, or out of range due to location control.