This template handles adding subject 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 subject categories. The book is passed in as parameter book.

"සැකිල්ල:BookCat/category/subjects/doc&oldid=13101" වෙතින් සම්ප්‍රවේශනය කෙරිණි