Every claim must be made on forms to be furnished by the organization and must contain all the information required by it. Each claim must be signed by the person entitled to compensation or by the person acting on that person’s behalf and, except in case of death, must be accompanied by a certificate of the employee’s doctor stating that the employee was physically examined, stating the nature of the injury and the nature and probable extent of the disability. For any reasonable cause shown, the organization may waive the provisions of this section.