noun
colophon; postscript; publication details
Refers to the note at the end of a book or manuscript giving the title, author, date of completion, or publication information. In modern contexts, it can also mean a postscript or verification note.
この古い写本の奥書には、筆写した日付と僧の名前が記されている。
The colophon of this old manuscript records the date of copying and the name of the monk.
本の奥書を見れば、初版の発行年がわかる。
You can find the year of the first edition by looking at the publication details at the end of the book.
奥付 is the standard modern term for a book's colophon or imprint page, while 奥書 is more traditional and often used for older manuscripts or handwritten notes.
Compound of 奥 (oku, 'inner part, back') and 書 (kaki, 'writing'). The exact historical derivation is uncertain, but it refers to writing placed at the back of a book.