Case LEDs & Buttons

[Manger74]

While working on the PCB, i was thinking about buttons and LED's.
The MiST and also the MiSTer have three buttons and three LED's.

Power (system power)
Core (core ready)
IO (drive activity)

Reset
Menu
User (core defined)

The MiSTle cores use the six LED's in different ways...
Maybe we should define a standard for the MiSTle cores and boards?

Power LED hardwired to the board's +3,3V?
LED 1 to 2: Core & IO analogue to MiST & MiSTer?
LED 3 to 6: core specifiic?

The most important, in my opinion, would be a standardized combined drive activity LED, to prevent data loss and drive corruption when powering off the system.