The Flashman books , George MacDonald Fraser. A Secret History , Mary Gentle. It's a translation of fifteenth century documents, and footnotes explain terminology and offer commentary. Brotherhood of War and Saga of the Corps series by W.E.B. Griffin. Book , Robert Grudin.
Footnotes take over the novel.
Time Enough for Love , Robert A. Heinlein. Rogue Roman , Lance Horner. Battlefield Earth and the Mission Earth dekology, L. Ron Hubbard . Biggles Defends the Desert , Captain W.E. Johns. Probably just in this particular edition, published by Red Fox in 1993.