50.Section 15 confers a right on any person who owns or who has an interest in a qualifying estate to lodge a caution. A qualifying estate is a legal estate which relates to land to which the caution relates, and is one of the four registrable estates i.e. an estate in land, a rentcharge, a franchise or a profit à prendre in gross. Subsection (3) provides that the owner of a freehold estate, or of a leasehold estate with a term of more than seven years, cannot lodge a caution in respect of that estate. This is a new provision. The reason for it is that cautions against first registration are not intended to provide a substitute for first registration. The goal of total registration requires that a person with an unregistered legal estate that is registrable should register it. This prohibition will, however, not apply for two years after the provisions are brought into force. Under the transitional arrangements in paragraph 14 of Schedule 12, the new provision will have effect two years after the rest of the section is brought into force. At the end of the two year period, subsisting cautions against first registration lodged by the landowner will cease to have effect unless an application has been made for first registration.