1. Black Women are kept as house slaves
2. Black m*n, if allowed to exist at all, work menial jobs away from the sight of whites
3. Black Women can be bred by white men
4. If the offspring of such a breeding is female, it is allowed to live and will grow up to also be a house slave; if male, it is aborted
5. Once the female offspring of these breedings is sufficiently white (let's say, 90+%), it is classed as a fully free citizen
6. Laws are in place to protect nigress slaves so they cannot be abused to an unpleasant degree.

This would be the ideal situation.