Wyoming MCP 18. Letters of Guardianship is a document that is used in the state of Wyoming to appoint a guardian for a minor or incapacitated adult. This document is a written statement made by a court that outlines the rights and responsibilities of the person appointed as guardian, and is required when starting the guardianship process. There are two types of Wyoming MCP 18. Letters of Guardianship — Temporary and Permanent. The Temporary Letter of Guardianship is issued by the court and is valid for up to six months. The Permanent Letter of Guardianship is issued by the court and is valid until the minor or incapacitated adult’s 18th birthday or if the incapacitated adult is determined to no longer need a guardian. Both letters outline the rights and responsibilities of the guardian including decision-making authority, financial responsibility, and legal authority.