Definitional rules are a type of business rule that form theories or produce information. They represent something that is fundamentally true or untrue about some concept within the organization. Unlike behavioral rules, which are about people's behavior, definitional rules constitute operational knowledge of the organization. They cannot be violated but can be misused. For instance, a definitional rule might be used to classify different categories of customers based on contractual agreements or order quantities.
References: The information provided here is verified and aligned with the concepts presented in the Business Analysis Body of Knowledge (BABOK) and other learning resources provided by the International Institute of Business Analysis (IIBA). Specifically, it reflects the understanding of business rules as outlined in the resources related to business data analytics certification and essential reading resources provided by IIBA12.