Certificate of contested validity
In United Kingdom patent law, a certificate of contested validity is an order usually made by the Patent Office, Patents Court (a division of the High Court) or Patents County Court after a patent infringement action in which the validity of the patent is unsuccessfully challenged. Section 65 of the UK Patents Act 1977 allows the Court to make such an order.
Source: Wikipedia — Certificate of contested validity (CC BY-SA 4.0)