keyboard - Has the '5' key on the numeric keypad ever had an alternate function in hardware?

Every modern keyboard that has a numeric keypad, at least that I can think of, has alternate functions printed on the keypad numbers, i.e.:

• 0 is Insert


• . is Delete


• 7 9 3 1 are Home, Page Up, Page Down and End


• 8 4 6 2 are the arrow keys

Has the 5 key ever had an alternate function printed on it?

I'm mainly thinking about back in the midsts of computing history when all sorts of incompatible keyboards were made and featured no-longer used keys, like the Space Cadet:

(Note, I did find out that Java names the key "Begin". Has a physical keyboard ever used that inscription?)

Answer

I looked at my library of images, and found two examples that seem relevant.

1:

that seems to be using the numeric 5 for… something related to cursor manipulation. I am not sure what it does.

2:

with a trackpad built into it. It seems that the numeric keypad doubles as hardware “mouse keys”, with extra arrow keys and 5 labeled as “Click.”