Adoption Bhimashya v. Janabi @ Janawwa, 2007 (3) RCR (Civil) 534 (SC) Custom must be ancient, certain and reasonable as is generally said. It will be noticed that in the definition in Cl. (a) of Section 3 of the Act, the expression 'ancient' is not used, but what is intended is observance of custom or usage for a long time. The English rule that a 'custom, in order that it may be legal and binding, must have been used so long that the memory of man runneth not to the contrary' has not been strictly applied to Indian conditions. All that is necessary to prove is that the custom or usage has been acted upon in practice for such a long period and with such invariability and continuity as to show that it has by common consent been submitted to as the established governing rule in any local area, tribe, community, group of family. Certainty and reasonableness are indispensable elements of the rule. For determination of the question whether there is a valid custom or not, it has been emphasized that it must not be opposed to public policy. A "custom", in order to be binding, must derive its force from the fact that by long usage it has obtained the force of law, but the English rule that "a custom in order that it may be legal and binding, must have been used so long that the memory of man runneth not to the contrary" should not be strictly applied to Indian Conditions.