Doctrine of factum valet

1. CONVENTIONAL CUSTOM :
This custom arose out of contract, Parties to contract generally used certain terms for their contract to be observed in their transactions. The Sale of Goods Act., Partnership, Agency, etc., are based on the conventional customs.
2. PERSONAL CUSTOM :
It relates to only a few individuals and it does not involve the people in general. For e.g., Easementary right is out of a personal custom.
3. LOCAL CUSTOM :
It is observed in a particular locality alone. For e.g., in a particular locality, there may be a custom to conduct marriage after performing certain ceremonies, which may not be present in any other locality.
4. GENERAL CUSTOM :
It is observed throughout the State. It is part of the common law of the land.

ESSENTIALS FOR A VALID CUSTOM :
1.REASONABLENESS:
The custom must be reasonable. It should not affect the society in any way. It should satisfy the principles of Natural justice. If a custom is unreasonable, then it is not valid and will not become a law For e.g. if a custom recognizes that a woman can marry more than one man, it is unreasonable and will not become a law.
2.CONFORMITY:
The custom should be in conformity with the established law of the land. If a custom is inconsistent with the law of the land, then it is invalid. For e.g. slavery is an offence under the Indian Penal Code, if a custom recognises slavery, then such custom is invalid.
3.OPINION :
The public must feel that the particular custom is beneficial for them. They must think that such a custom is a binding rule of the community and it should not be of individual choice.
4.OBSERVANCE :
A mere practice of custom will not become law. It must be observed freely and voluntarily.
5.IMMEMORIAL ANTIQUITY :
The origin of the Custom should be from time immemorial. the origin should not be traced. No living man must remember its origin. Recent customs or modern customs are not valid customs. Fashion is not custom. In England, a custom must have existed continuously from 1189 A.D. to be considered valid.
6.CONTINUITY:
The custom should be followed without interruption. It must be followed continuously.
7.PEACEFULNESS :
The custom must have been observed peacefully. In other words, it should not be protested in any way by the public or part of the public.
8.CERTAINTY :
The custom must be certain and definite. It should not be vague. If a custom is indefinite, then it is invalid.
9. CONSISTENCY WITH OTHER CUSTOMS :
The custom should not be opposed to other customs. Suppose two different customs exist which are inconsistent to each other, then both the customs are invalid.