During production of "The Nagus", the episode went by the title of "Freinds & Foes".
Ira Steven Behr, who started on the series as a Supervising Producer and would later become an Executive Producer for DS9, is best known for creating the Ferengi Rules of Acquisition.
Quark orders Rom to recite the first Ferengi Rule of Acquisition: Once you have their money, you never give it back.
Grand Nagus Zek quotes Quark the sixth Ferengi Rule of Acquisition: Never allow family to stand in the way of opportunity.
Quark: So, Rom....you were gonna toss me out an airlock.
Rom: Forgive me, brother.
Quark: Forgive you?! Why, brother...I didn't think you had the lobes. Such wonderful treachery deserves a reward. I'm going to make you the assistant manager of policy and clientele here at Quark's.
Rom: What exactly does that mean?
Quark: How should I know? I just made it up. Come on, I'll by you a drink.