[quote="Mintaka, post:2, topic:341130"]
Actually, they don't. They just forgot to make a clear heading for "Historical Books" after the Pentateuch. "Historical Introduction" is clearly referring to the Historical Books, though.
After that, the headings are in the same blend-in green underlining for Biblical Novellas, Wisdom Books, Prophetic Books, New Testament, Gospels Introduction, New Testament Letters, and Catholic Letters.
Some of the NT books are apparently in standalone categories, or otherwise don't have a heading. 1 and 2 Maccabees are historical books, not "Biblical Novellas" in any way, shape, or form. We even know what book one of them is condensed from, and the pain in the butt that the editor had, in turning a multi-volume history book into something short and sweet. Acts is not a Gospel.
If you're expecting wonderful, well-organized webpages from NCCSB, you've got the wrong NCCSB.
Oh, I should add that we do have some historical examples of 'Octateuchs' - the Pentateuch with Joshua, Judges and Ruth bound with them. Of course this arrangement is only possible in the Christian ordering of the OT books.