In the interpretation of parks and watercraft rules, their provisions shall be construed as follows:
(A) "Rules" shall mean "rules and regulations";
(B) Any terms in the singular shall include the plural;
(C) Any term in the masculine shall include the feminine and the neuter;
(D) No provision hereof shall make unlawful any act necessarily performed by any officer or employee of the department of natural resources in line of duty or work as such, or by any person, his agents or employees, in the proper and necessary execution of the terms of any agreement with the division or department of natural resources;
(E) If any paragraph or provision of parks and watercraft rules shall be determined to be invalid, such determination shall apply to the particular paragraph or provision, and all other provisions of parks and watercraft rules shall remain valid and in effect.