Documentation on making new checkers variants

[Rein Halbersma]

Is there any documentation on how to define new variants for Winboard Alien? I'd like to adapt my checkers/draughts library to Winboard. My library can play several rules variants on arbitrary rectangular board sizes (with exotic promotion and capture removal rules), so I think I have to override the Nebiyu versions of 8x8 and 10x10 checkers/draughts. Any help on getting started would be much appreciated!