This document discusses the concept of custom as a source of law in Hindu law. It defines custom as a habitual course of conduct generally observed in a community. There are three types of customs: local customs which prevail in a defined locality, general customs which are operative throughout a realm, and family customs which concern adoption, marriage, descent, and property devolution within a family. For a custom to be considered valid, it must be reasonable, certain, ancient, not opposed to any law or morality, continuous, and have obtained the force of law through long usage and acceptance. The document provides examples and explanations of each type of custom and the essential requirements for a custom to be recognized as a valid source of law.