Section 93.670 - Power of attorney and executory contract for sale or purchase of lands; recordability; effect as evidence; revocation(1) Every letter of attorney, or other instrument containing a power to convey lands, as agent or attorney for the owner of such lands, and every executory contract for the sale or purchase of lands, when acknowledged or proved in the manner prescribed for the acknowledgment or proof of conveyances, may be recorded in the county clerk's office of any county in which the lands to which such power or contract relates is situated. When so acknowledged or proved, such letter, instrument or contract, and the record thereof when recorded, or the certified transcript of such record, may be read in evidence in any court in this state without further proof of the same.(2) No letter of attorney, or other instrument so recorded, is deemed to be revoked by any act of the party by whom it was executed unless the instrument containing such revocation is also recorded in the same office in which the instrument containing the power was recorded.