Moreover, among the types of conservation units, there is the Private Natural Heritage Reserve (RPPN), a natural reserve with a perpetual lease: once an area is given the status of RPPN in the Real Estate Register Office, it can not be downgraded. For an area to get this title however, it has to fall into one of the following categories:〔【出典】Global Voices Online◆【英文】Danilo Goncalves ◆【和訳】Izumi Mihashi ◆【License】CC BY 3.0 〕