“ T—S.T.D.—B”
An interesting discussion on the origins of some printed mystery notations in a 1966 Penguin book: "The bottom of page 33—and only page 33 – in my 1966 Penguin edition of Saul Bellow’s “Seize the Day” has “T—S.T.D.—B” written on the bottom left, opposite the page number. What does it stand for?"