Every contractor shall issue to the employer, a contract holder, or other person or association in whose name a contract is issued, for delivery to each person covered by a group contract, a certificate setting forth in summary form a statement of the essential features of the contract coverage, and to or for whom the benefits thereunder are payable. If family members are covered, only one certificate need be issued for each family. In the event that contracts are changed or amended, new certificates or a clearly understandable amendment to existing certificates shall be promptly furnished. The style, arrangement, and over-all appearance of the certificate shall not be less favorable than the requirements imposed by WAC 284-44-030. Such "certificate" may be in the form of a comprehensive booklet or brochure. The form of such certificate shall be filed with the insurance commissioner.