Forms and Documents, Download. How to fill out the Postal Life Insurance Proposal Form Instructions?1. Read through the entire form to understand the required information. This document appears to be a proposal form for postal life insurance. Fill out the Proposal Form. "In every case where a proposal for Postal Life Insurance or Rural Postal Life. Definition of Proposal Form. A proposal form is a formal application document that an individual fills out when applying for an insurance policy. The consent of the appointee should be obtained at the same time as the appointment is made. Provision for this is made in the Proposal form.