Code of Federal Regulations Title 43. Public Lands:  Interior § 43.3100.3–1 Enforceability

(1) The names and addresses of the parties thereto;

(2) The serial number of the lease to which the option is applicable;

(3) A statement of the number of acres covered by the option and of the interests and obligations of the parties to the option, including the date and expiration date of the option;  and

(4) The interest to be conveyed and retained in exercise of the option. Such notice shall be signed by all parties to the option or their duly authorized agents. The signed copy or notice of option required by this paragraph shall contain or be accompanied by a signed statement by the holder of the option that he/she is the sole party in interest in the option;  if not, he/she shall set forth the names and provide a description of the interest therein of the other interested parties, and provide a description of the agreement between them, if oral, and a copy of such agreement, if written.