Two major changes here. First, Oddity High's itch.io materials have switched from being strictly free to being PWYW. In practice, the PDFs are still free, but now you can send some money my way if you wish to support me or the project. The second is that I've adjusted the name to make it clear that the currently available documentation is a preview build. The full book will be released Soonᵀᴹ and will be sold for its full price, but until then, enjoy the materials you can find here.