Keep an inventory of all real estate in the country (this has to be done anyway, in order to do city planning).

sensible planning? what's that? in the UK registration only has to take place at change of ownership, and consequently 40% is still unregistered, and that 40% is mainly owned by the Aristocracy, who are one of the main groups avoiding tax.

Land Registry : Press notice

Land Registry - the government department responsible for registering land ownership in England and Wales - is encouraging landowners to voluntarily register their land, securing their ownership with state-backed registration. In North Yorkshire 42 per cent of land remains unregistered. In England and Wales the amount of unregistered land is just under 40 per cent.