The Assembly Information Manual has special notation at the lower right of some pages of "DOCUMENTATION REQUIRED". It is just above the revision record box. A number of pages show it was later removed. I noted the M20 pages on the 1969 manual have several marked. Is this something to do with an outside sourced part like a Hurst shifter or similar? C60 pages have some notation about this- Curiosity about what this references?? Recording number of times installed??