There are several 3D Cadastre scoping options, which need to be investigated in more detail, and the result will define the scope of the future 3D Cadastre in a specific country: What are the types of 3D cadastral objects that need to be registered? Are these always related to (future) constructions (buildings, pipelines, tunnels, etc.) as in Norway and Sweden or could it be any part of the 3D space, both airspace or in the subsurface as in Queensland, Australia? In case of (subsurface) infrastructure objects, such as long tunnels (for roads, metro, train), pipelines, cables: should these be divided based on the surface parcels (as in Queensland, Australia) or treated as one cadastral object (as in Sweden). In case of subdivision, note that to all parts rights (and parties) should be associated. For the representation (and initial registration) of a 3D cadastral object, is the legal space specified by its own coordinates in a shared reference system (as is the practice for 2D in most countries) or is it specified by referencing existing topographic objects/boundaries (as in the 'British' style of a cadastre). Note that there can be a difference between the 3D ownership space and the 3D restriction space; e.g. one can be owner up to ±100 m around the earth surface, but only allowed to build from -10 to +40 m. Both result in 3D parcels, that is, 3D spatial units with RRRs attached. The ownership spaces (parcels) should not overlap other ownership parcels, but they are allowed to overlap other space; e.g. restriction parcels.