Officer Billings

It just occurred to me -- do you suppose Officer Billings got that name because they wanted him to have some sort of billing (not top billing, obviously, but at least his name in the credits)? In his first four appearances, Billings had a first name (Todd 3 times and Jack once), but after that he was just Billings.

Luis Delgado appeared in 42 episodes of the original Rockford series (putting him fourth, behind only Garner, Beery, and Santos), playing Billings 33 times (credited in 27 of those), and as miscellaneous characters in 9, including the pilot movie (in which he played a background character named Luis Delgado!).