That's a nice photo Hoss and that's a very good lesson about photographing a carving or marker for that matter. I always take several photos from lots of angles, close ups and wide shots. Digital cameras make it easy to do that and not spend a fortune. You just never know when you might need to see something and can't be at the site or when something may disappear or change.
I'll have to take your word on the meaning since it sounds like you already worked it out. I don't deal much with tree carvings in my neck of the woods, mostly rock carvings and carry around type maps.
Autocad, huh? That's a new one on me.
Here's one for ya. Found this one working a line. The flat top boulder was imbedded into the ground and the center of the boulder was dug out. Then they placed a rock in the dug out part and filled in back in with dirt.