书号 Traditional form: 書號 Pinyin (reading): shūhào Definitions: book number (esp. ISBN) Characters: 书 - book, letter, document; writing 号 - mark, sign; symbol; number; to call, to cry, to roar Traditional characters: 書 - book, letter, document; writing 號 - mark, sign; symbol; number; to call, to cry, to roar