This Authorized Representative form is enclosed for this purpose. If you want to authorize someone to represent you at the hearing, please complete this form.A Letter of Authorization authorizes payment for medical services received over 12 months before the current month. A letter of authorization should contain all the necessary information in a precise yet humble manner. Let's see why it is important to do so. California Penal Code Section 602(o) only allows a property owner to file a trespassing arrest authorization letter for a period not to exceed 12 months. I know that California residencies require the Postgraduate Training Authorization letter (aka PTAL or California Letter). Why do I need to complete this form? 3.0 Submitting an application for authorization.