: not convertible back to ISBN-10 for books published since 1 January 2007 (or any book using another prefix than "978-"); converting old books back to their original ISBN-10, published up to December 2006 (and found with an ISBN-13 in some digital catalogs), requires dropping the "978-" prefix AND recomputing the last check digit (or letter 'X') with the former algorithm.
: specific editions should be used with instances of ‘version, edition or translation’ (Q3331189); if necessary, create a new item and link via ‘has edition or translation’ (P747)
: Audiobooks does not use the ISBN system, If the item is about multiple editions of a literary work then those should be split into their own seperate items