(1)A person may apply to the registrar for the entry of a restriction under section 42(1) if—
(a)he is the relevant registered proprietor, or a person entitled to be registered as such proprietor,
(b)the relevant registered proprietor, or a person entitled to be registered as such proprietor, consents to the application, or
(c)he otherwise has a sufficient interest in the making of the entry.
(2)Rules may—
(a)require the making of an application under subsection (1) in such circumstances, and by such person, as the rules may provide;
(b)make provision about the form of consent for the purposes of subsection (1)(b);
(c)provide for classes of person to be regarded as included in subsection (1)(c);
(d)specify standard forms of restriction.
(3)If an application under subsection (1) is made for the entry of a restriction which is not in a form specified under subsection (2)(d), the registrar may only approve the application if it appears to him—
(a)that the terms of the proposed restriction are reasonable, and
(b)that applying the proposed restriction would—
(i)be straightforward, and
(ii)not place an unreasonable burden on him.
(4)In subsection (1), references to the relevant registered proprietor are to the proprietor of the registered estate or charge to which the application relates.