Noun
(publishing, broadcasting) Less important or less hard-hitting material relegated to the later pages of a print publication or the later stages of a television broadcast.
Used other than figuratively or idiomatically: see back, book.
Source: en.wiktionary.orgI learned quickly, as I tell my graduate students now, there are no answers in the back of the book when the equipment doesn't work or the measurements look strange. Martin Lewis Perl
It's not as if I'm trying to write crossword puzzles to which one might find an answer at the back of the book or anything like that. Paul Muldoon