Instructions for completing the Third Party Letter of Authorization (LOA). Need help downloading or filling forms?A letter of authorization lets you act on behalf of another person or a business to pick up mail or apply for postal services. Please call any of our offices if additional information (other than fee quotes) is needed. Please also have proof of valid insurance and proper identification. A new medication form must be completed at the beginning of each camp season, for each medication, and each time there is any. Applicant must fill out and sign Application Form. If Applicant is not property owner, provide signed owner authorization. Montgomery County or other cities or counties in the Washington metropolitan region. Attach copy of program participation letter, dated within 30 days.