If you remember, the first edition(s) of the GCOR included train order and timetable operation, and signal aspects. I would have to look through my collection, but I remember getting a new GCOR about 1989 and wondering why it was so small - I think it was the second or third edition that dropped train orders.

Remember if there was an expiration time on your track warrant, you were required to provide flag protection if you weren't in the clear? And of course, line 15 for relief from flag protection (FRED wasn't too good at that). Not being able to run because you weren't on the MOW lineup? Didn't the early GCORs use the century old numbering?

Yes, the rules have changed due to evolution. And many have gotten clearer as to their meaning and no longer conflict with other rules. But too many of them are absolute garbage now due to the feds and attorneys. Notice how Rule 26 was one to three paragraphs for a century, and now requires that many pages?