(1) A mortgage must be discharged upon the record by the county clerk in whose custody it is recorded whenever there is presented to the clerk a certificate executed by the mortgagee or the mortgagee's personal representative or assignee, acknowledged or proved and certified as prescribed in this chapter that entitles a conveyance to be recorded, specifying that the mortgage has been paid or otherwise satisfied or discharged.
(2) Every certificate and the proof and acknowledgment must be recorded at full length, and a reference must be made to the book and page containing the record in the mortgagor and mortgagee indexes as to the discharge of the mortgage.