A more thorough explanation:

Definition: Common Parliamentary Law refers to the body of rules and precedents that govern the proceedings of legislative bodies and other deliberative assemblies. It is also known as parliamentary procedure.

For example, in a meeting of a student council, the members follow certain rules and procedures to conduct the meeting. These rules are based on common parliamentary law and are designed to ensure that the meeting is conducted in an orderly and fair manner.

Common parliamentary law is based on precedents of legislative and administrative bodies. In America, the law has been evolving based on court decisions, and a considerable volume of judicial precedents has accumulated. The application of parliamentary rules to new situations is subject to the same rules of reasoning as the application of established common law rules to new legal situations.

In the absence of adopted rules of order, the basic principles and practices of parliamentary law apply. A parliamentary manual is evidence of the general parliamentary law. A deliberative assembly that has not adopted any rules is commonly understood to hold itself bound by the rules and customs of the general parliamentary law.