Abstract Derivation of Laws from various sources and agitation in legislation and lack of experience on the part of the legislator have caused disorder among legal items in some cases.It has led to ambiguities that made the scope of law institution unclear, so that Oval Casserole the efforts of the lawyers to clarify the concepts and scope of the terms have failed.There are three terms in Iranian penal code: Ezen (permission), consent, and exemption clause whose scope is so vague that indeed physicians resort to and insert both MYRRH GUM consent and exemption clauses in medical contracts.
Therefore recognizing each institution, their effect and distinction seems to be essential.