This document outlines the rules regarding who can administer an estate under Philippine law. It discusses the different types of authority that can be issued: letters testamentary to an executor named in a will; letters of administration to someone administering an intestate estate; and letters of administration with a will annexed if the executor is incompetent. It details who is competent to serve as an executor or administrator, such as a resident adult, and who is not, like a minor. It also addresses related issues like whether a married woman can serve, what happens if co-executors are disqualified, and the scope of an administrator's authority.