Evidence of representation or legitimate interest may be either individual authorization cards, or by petition. In either case, the petition or card must show address of, and be signed and dated by, the employee expressing an intent to be represented by a specific employee organization. A card or petition signed and dated by a public employee less than one year prior to the date on which the petition for certification was filed shall constitute prime facie evidence of continuation of such authorization.
Kan. Admin. Regs. § 84-2-4