Sui generis
Sui generis (; ) is a Latin phrase that means "of its (his, her, their) own kind; in a class by itself; unique."
Sui generis
The grant of private hire vehicle (taxicab) operators licences by local authorities frequently has a condition attached that the appropriate "sui generis" change of use planning permission is granted to those premises to ensure those businesses cannot trade lawfully without the appropriate planning consents.