I suspect there might be a difference between US and UK practice as far as copyright goes. In the UK, copyright is presupposed so you don’t need to do anything to assert it. In the US it may be a bit less clear cut
@daedalus The law in the USA is basically the same, copyright rests with the creator as soon as the creation is in a tangible form. The difference is litigation, America’s national sport. To defend, or attack, is far less complex and expensive if you’ve registered the copyright. But, an important point, just putting the C-mark on your work, without registration, has no effect when it comes to litigation.