rule established by an organization or community to regulate itself, within limits set by a higher authority

A By-law is a rule made by an organization to regulate itself. Sometimes it is also spelled bylaw or bye-law.

"Byelaws for good rule and government" in Ripon, North Yorkshire

In the United Kingdom, Canada, and some Commonwealth countries, the local laws made by municipalities are called by-laws. This is because the laws are regulated by the central governments.