(1) A mortgage certificate is issued on the mortgage.
(2) The issuance of the certificate may be excluded. This exclusion also may be effected subsequently. The exclusion requires agreement between the creditor and the owner as well as the entry in the Land Register; the provisions of section 873 (2) and of sections 876 and 878 apply accordingly.
(3) The exclusion of the issuance of the certificate may be cancelled; the cancellation is effected in the same way as the exclusion.