Speaking of geotagging and emanation, these messages were recently found nailed to an electrical pole in Echo Park. There seems to be an indicator for North, and possibly a message reading UR. I think the lower-right fragment is repeated, and the lower-left fragment is missing (from above view). The reverse faces seem to further reiterate UR by saying TOUR, MOORE, and DETOUR.
WASTE system? As I was showing these to Ed, my computer said SIGIL.
