Duchy of Cornwall
Prince William, the Duke of Cornwall as a Harbour Authority is subject to the Environmental Information Regulations (EIR). 

 Legal ruling The Upper Tribunal ruled in 2016 that the Duke was subject to EIR when acting in this capacity only in the following cases: The A-G for the Prince of Wales v the IC and Mr Michael Bruton [2016] UKUT 0154 (AAC)

The Duchy itself was found not to be a legal person in this case and therefore not subject to EIR.  The Duchy has been left on the site because it is run as a separate entity and users may wish to make requests to it.