Nathan, I would disagree in this respect. When you first mark a course, I think it's good to state how a point is marked and with what designation (for me, usually a letter). It would be up to the race director(s) to keep the marks refreshed, or not, but at least you're giving them good information. For some events, that change annually but not by a whole lot, it's good to have a coding system so that the current course marks can be distinguished from marks from other years.
Also, just to be clear, our descriptions should give enough information that the point could be re-established even if no paint or nail is to be found.
I'm leery of stating things just to an RD. I feel like the runners should be the ultimate "police" who can check, if they are so inclined, to see if the race is being set up correctly.
(Of course that would mean that the official, certified, course map is made freely available to the runners-- something too many races neglect, instead giving out only a "non-technical" map for public consumption.)
Keith, I feel your pain! Sometimes the homeowner is the National Park System, and can they raise cane! (or is that Cain?)