[EricH]

Originally Posted by chrisinmd

I believe it's legal to use lighted switches, but you need an external power source. Would someone else please chime in because we want to do some feedback on the control board and the OI doesn't put out enough power for LEDs and switches, as shown below.

If it's legal to use lighted switches, but you have to run them off an external power source, it's illegal.

<R78> All equipment connected to the Joystick Ports of the IFI Operator Interface must be powered solely through the power available through the port. External power sources of any type are not permitted on any equipment connected to the Joystick Ports. Portable computing devices may not be connected to Joystick input ports on the Operator Interface. Power-passive devices (e.g. joysticks that draw their power solely through the IFI Operator Interface joystick port) are permitted.

(Emphasis mine)
So, if you follow the method chrisinmd proposes, you won't be allowed to use a lighted switch.