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By-laws are legislation formed by public bodies or local authorities, and approved by the appropriate Minister. By-laws have the same legal status as other forms of delegated legislation, and are therefore a form of subordinate or secondary legislation. In some jurisdictions (e.g. the United States), by-laws are most commonly a public company's (or corporation's) administrative provisions that are either attached to the articles of incorporation or kept privately. However, in English law by-laws are generally regulations made by a local authority or public body, such as a town or a railway.

See Primary legislation, delegated legislation.