Alphabeticals - not yet prepared
Keywords - selected words reflecting the content (and usually from the title) (alphabetical) (which is not due to be prepared until 2023)
Numericals - list of pages, presented in numerical order (which is not due to be prepared until 2023) (ascending)(Eventually)
Subjects - (which is not due to be prepared until 2023) much the same as the keywords, but more ordered and helpful