The skilled person
3.In its Particulars of Claim Nissen contended that the skilled person is a designer and manufacturer of mobile warning devices for road traffic. The Defence pleaded that the skilled person is a designer, manufacturer or user of such devices. Both skeleton arguments stated that the parties were agreed on the identity of the skilled person, so they apparently felt that there was no difference between them that mattered. 4.The invention claimed in the Patent would be of practical interest to a designer of mobile warning devices for road traffic. Such an individual would work for, or at least with, a manufacturer of those devices and will broadly know how they are made. He or she will also of necessity know how the devices are used since they must be designed to serve the market. The design and use of the devices is highly regulated and it was agreed that the skilled person would be familiar with the relevant regulations. 5.This is a UK patent. It follows that the skilled person will be based in the UK and it is the UK regulations and use of traffic signage in the UK which form part of the skilled person’s common general knowledge. I state that obvious point (it was not in dispute) because it came to have some relevance.