 Descriptor revision makes it possible to investigate operations of change more generally, and to discuss properties that can hold for operations with different types of the success conditions. Let \( \Psi\) and \( \Xi\) be descriptors, i.e. sets of sentences containing the \( \mathfrak{B}\) operator. Let \(K ⊩\Psi\) denote that \(K\) satisfies all the conditions in \(\Psi\). Some examples of such general properties of descriptor revision are: