The recording of all instruments by the roll form of microfilm may be substituted for the method of recording instruments in books, and the filing of all documents by the roll form of microfilm may be substituted for the method of filing original documents. If this method of recording instruments on microfilm or filing documents on microfilm is used, the original instruments so recorded and the original documents so filed need not be retained after the microfilm has been verified for accuracy and quality, and a security copy on silver negative microfilm in roll form must be maintained and filed off premises under safe conditions to insure the protection of the records and shall meet the microfilm standards as prescribed by the State Records Administrator as provided in sections 84-1201 to 84-1220. The fee books shall provide the proper index information as to the microfilm roll and numerical sequence of all such recorded instruments and of all such filed documents. The internal reference copies or work copies of the instruments recorded on microfilm and of documents filed on microfilm may be in any photographic form to provide the necessary information as may be determined by the official in charge.