1972 RPO list Question

[cbeerman]

Hey guys I recently purchased a 1971 printing of a GMC 67-72 master parts book x-172001 and in the back of the binder there looks to be a copy of the Optional Equipment Installation Parts List (R.P.O.) x-172005 dated June 1972
basically it is a list of the 1972 RPOs and the part numbers associated with that RPO
Check out the attached pic for the RPO U-16 Tach
I was just wondering if this is anything worth sharing or if all the parts books have this list.