>>3863
Looks more like a control point for construction. See that kind of notation spray painted on sidewalks, roads, and markers along a road where they plan on putting in very long runs of pipe. Like 1100'+28'. 1100' is the actual control point, but go another 28' to get to that particular location on that run. The 5D is probably referencing POTUS. Therefore go to this location along the border wall for POTUS...as you can see, he signed the 3rd one to the right. So eventually it'll be a historical site, and they know where to find this location later on.