3.3 Recent developments 57 had defined the same term as "a . . . requirement . . . expressed in non-procedural and non-technical form . . . [which] represents a statement about business behavior." While this definition did not exclude "laws of physics, . . . legislation, . . . regulations, . . . external standards and best practices," it restricted business rules to those that are properly expressed. I agree that it is important to ensure that all rules governing an enterprise are expressed declaratively and in natural language, but these are quality criteria governing rule statements rather than restrictions on what makes a business rule. 3.3.7 Rule statements and advice statements Although it is important to clearly state prohibited or obligatory behavior (using rule statements), it may be just as important to clearly state what is allowed or not obligatory. This can be done using advice statements, such as "an employment application may omit the applicant's date of birth." Why are these important? To quote the SBVR: "There are many possible reasons, but probably foremost among them are to re-assure workers or others that some degree of freedom does exist; to use as a basis for admonishing workers about ap- plying some rule that actually does not exist; or to `remember' the resolutions to some rule-related