The title of the episode is shorthand for Semper Fidelis, which is a Latin phrase, meaning "Always Faithful." Semper Fidelis is the motto of every Marine-an eternal and collective commitment to the success of our battles, the progress of our Nation, and the steadfast loyalty to the fellow Marines that they fight alongside.
Stephen Lang (Angus Boone) guest starred in Law & Order: Criminal Intent as a German anarchist in Revolution (2009).