What does it mean when you sign a waiver and your on parole?

My friend was on parole for five years . He did four years no trouble . He got another charge and when he went to jail his parole office had him sign a waiver . He didn't know what he was signing but signed it anyway. Does this mean that he only faces six months or does this mean that he has to do his hole time left on his parole. His max release day is Feb 16 2016. His new charge was domestic battery . Please help me to understand this waiver and what it could mean.