Stallman would have to abide by two rules: no C (and that includes C++) and no niggers.
In every stage of the bus boycott we have been oppressed and degraded because of black, slimy, juicy, unbearably stinking niggers … African flesh-eaters. When in the course of human events it becomes necessary to abolish the Negro race, proper methods should be used. Among these are guns, bows and arrows, slingshots and knives… All whites are created equal with certain rights, among these are life, liberty and the pursuit of dead niggers.