I'm guessing there may have been an earlier,maybe identical system for dating Shimano hubs,preceeding 1976.The ones I have are packaged in the same tan boxes with blue and black stripes as other hubs I have from the early road models.These road hubs are spaced 120mm in the rear,placing them well before the 2001 date that the CR website indicates.The packaging for Shimano products had changed many times by this point.Hmmmmmm......
Cheers,
Todd Kielman
chicago il.