Why can’t we use maps to link to maps? An abstract, blocky shape is easy to recognise with the right software as AR projects have shown, but the marker (qr codes, fiducials, etc) often isn’t human-readable or bears little relationship to the content. Mapcodes would present a simplified map which, if you know the area, you could recognise, but more importantly, your mobile device could identify and point to the digital map for that area, the tfl route, whatever. The gap between the representation and the digital tools is bridged.