The vararg feature set supports variable-length argument lists and runtime-typed pointers.
If omitted: Any attempt to reference a method with the vararg calling convention or the signature encodings associated with vararg methods (see Partition II) shall throw the System.NotImplementedException exception. Methods using the CIL instructions arglist, refanytype, mkrefany, and refanyval shall throw the System.NotImplementedException exception. The precise timing of the exception is not specified. The type System.TypedReference need not be defined.
Part of Library: Vararg (see §IV.5.9).