The Ferengi Muk asks "Do I look like a Menk to you?" The Menk were the lesser evolved species of the planet Valakia (the Valakians being the dominant species) seen in Dear Doctor (2002). In that same episode, the Valakians mention the Ferengi, but no one on Enterprise has ever heard of them.
The script goes out of its way to not reveal the name of the race to which the marauders belonged, since official contact wouldn't occur until well over two centuries later in The Last Outpost (1987). The same thing happened in Regeneration (2003).
Jeffrey Combs (who plays semi-regular Andorian Commander Shran in other episodes) plays the Ferengi Krem. This is the 2nd Star Trek series where Combs has played a Ferengi character. Combs also played the recurring character of FCA (Ferengi Commerce Authority) Liquidator Brunt in Star Trek: Deep Space Nine (1993).
Ethan Phillips plays the Ferengi Ulis. This would be the third time Phillips has donned the Ferengi ears and large forehead. Phillips appeared in Ménage à Troi (1990) as Dr. Farak, and in False Profits (1996) as the Grand Proxy (though that character was actually his regular Voyager character Neelix in disguise).
This episode states that the sixth Rule of Acquisition is "Never let family get in the way of profit." By the 24th century, it will have changed (slightly) to "Never let family get in the way of opportunity," as is revealed in The Nagus (1993).