What does CD stand for on model 99 savage?

The CD is a model 99 indicator which was used to show what difference,s there was to this version of the model 99.The model 99C was made from 1965-1997 and modeled after the model 99F.The difference between the model 99C and the model 99CD was that the model 99CD had a monte Carlo cheekpiece stock instead of the model 99C,s plain monte carlo stock.The savage model 99CD was made between the years 1975-1981.