PD on a hoop usually signifies palladium. Your ring may be palladium-plated if it's PD penned above it. HK is really a trademark that means Harriet Kelsall. They design and supply jewellery everywhere in the UK and also to other sites too.  Region hallmarks: Some countries have their own hallmarking methods. https://cristianwjugq.popup-blog.com/35952166/not-known-facts-about-jp88