The purpose of this Administrative Instruction is to establish and clarify procedures regarding. Immediate Supervisor.Use their name and formal title, such as "Dear Mr. Smith" or "Dear Dr. Johnson. Fill out the contact form or call us at (510) 645-1585 to schedule your free consultation. Add contact details, company name, and date. ACERA does not notify your employer; it is up to you. You must provide a letter of resignation to your HR department before you can retire. Learn how to write a professional resignation letter with our step-by-step guide, easy to use templates and helpful tips. ACERA does not notify your employer; it is up to you. You must provide a letter of resignation to your HR department before you can retire.