1. A statutory or contractual provision proclaiming that the document in which it appears, or a part of the document, cannot be repealed or amended. • Such provisions are considered ineffective.
“The one thing a sovereign legislature cannot do is truncate its own sovereignty by restricting its successors. A parliament sovereign today must also be sovereign tomorrow. What is technically called a clausula derogatoria is therefore ineffective: non impedit clausula derogatoria quo minus ab eadem potestate res dissolvantur a qua constituuntur (a derogatory clause does not prevent things from being dissolved by the same power which created them).” F.A.R. Bennion, Statutory Interpretation § 140, at 313 (3d ed. 1997).
2. A clause that a testator inserts secretly in a will, containing a provision that any later will not having that precise clause is invalid. • A derogatory clause seeks to protect against a later will extorted by undue influence, duress, or violence.
— Also termed clausula derogativa; clausula derogatoria.