Custom is the oldest form of law making. In primitive societies, human conduct was regulated by practices which grew up spontaneously and were later adopted by the people. According to Austin Custom is a rule of conduct which the governed observed spontaneously and not in pursuance of law set by a political superior.
Definition of Custom
Salmond Defined custom : "Custom is the embodiment of those principles which have commended themselves to the national conscience as principles of justice and public utility."
There are two kinds of Customs are as follows
According to Salmond a Custom has the force of law is of two kinds - Legal and Conventional
1) Legal Custom -
A legal custom is one the authority of which is absolute, one which in itself has the force of law. It is binding as a rule of law independently of any agreement between the parties. Legal Custom is again of two kinds being either local, prevalent and having the force of law in a particular locality only, or general having the force of law throughout the state.
2) Conventional Custom -
A Conventional Custom it is also known as usage, on the other hand, is conditional on its incorporation in agreements between the parties to be bound by it It is binding, not because of any legal authority but due to an agreement between the parties. it operates as an established the rule in some particular sphere of life, and is incorporated expressly or impliedly as one of the terms in a contract between the parties concerned. Most agreements consists of two parts, the terms expressed and the implied. The larger part of the most contracts implied and the law endeavors to find out the true intention of the parties with respect to those terms which are not in black and white from two sources, that which is reasonable and that which is customary. The letter part of the agreement is conventional custom .
See also.... Constituents of a valid Custom.