Letters of Authorization. This document authorizes a third party to receive customer information or act on a customer's behalf.Authorized Agent may sign form PDS346 ONLY IF ATTACHED to a Signed Letter of Authorization. 2. I authorize the San Diego Police Department (SDPD) to act as my agent for the purposes of enforcing all laws against any person found on the property. What is a Letter of Agency? The City recommends that property owners complete a Letter of Agency form with the San Diego Police Department (SDPD). Fill out the form below at your convenience, have it notarized, and upload it on this page to be sent to the appropriate Sheriff's Station in San Diego County. This form is used to tell the court you are authorized to appear for a plaintiff or defendant in a small claims case. You may also use this form to ask the. Please do NOT send FAXed or e-mailed duplicates of billings as this may delay processing and payment.