Template:BookCat/category/shelves/doc

Usage
This template handles adding shelf categories to a book category. Its logic is isolated here from the rest of BookCat/category because it's more elaborate than the rest of that template put together, so if included there it would obfuscate that whole template; it works by transcluding the book main page and parsing it to find the non-allbooks shelf categories. The book is passed in as parameter.