MODAF/NAF: An abstract Class that is extended by OperationalConstraint (A rule governing an operational behaviour or property.) and ResourceConstraint (A rule governing the structural or functional aspects of an implementation - this may also include constraints on OrganisationalResources that are part of an implementation).
DoDAF: Rule: A principle or condition that governs behavior; a prescribed guide for conduct or action. Subtype: Constraint: The range of permissible states for an object.