No, you got it right Zachary, ‘Propriety’ is just another way of saying ‘Locks by a particular Manufacturer’. So ‘Patent & Propriety’ means anything that’s got a patent or can be identified by a maker. Don’t forget you can always refine the contents of a category with the 'search' facility.

But it’s a good point you’ve made, I do intend to have a ‘sticky’ in each category giving a far more comprehensive description – lots of jobs to-do!