A more thorough explanation:

Definition: An arrêt de règlement is a decision made by Parliament in civil law to establish a rule of procedure, civil law, or custom.

Example: In France, an arrêt de règlement was issued in 1804 to establish the Napoleonic Code, which became the basis for civil law in many countries.

Explanation: This example illustrates how an arrêt de règlement can establish a significant legal framework. The Napoleonic Code was a comprehensive set of laws that covered everything from property rights to criminal law. Its influence can still be seen in many legal systems today.