Pin 20 reserved - does it need to be pulled high?

Looking through the schematics of the development board, I found that pin 20 of the ME connector is attached to jumper block P12 and is normally pulled high. Does this mystery signal need to be pulled high on my board or do I leave it disconnected?

No you need not do anything with pin 20. This pin is held high, internally, with its own pull-up resistor.