1. Once you have their money, you never give it back. ("The Nagus")
3. Never spend more for an acquisition than you have to. ("The Maquis, Part II")
6. Never allow family to stand in the way of opportunity. ("The Nagus")
7. Keep your ears open. ("In the Hands of the Prophets")
9. Opportunity plus instinct equals profit. ("The Storyteller")
10. Greed is eternal. (?)
16. A deal is a deal. ("Melora")
17. A contract, is a contract, is a contract... but only between Ferengi. ("Body Parts")
18. A Ferengi without profit is no Ferengi at all. ("Heart of Stone")
21. Never place friendship above profit. ("Rules of Acquisition")
22. A wise man can hear profit in the wind. ("Rules of Acquisition")
31. Never make fun of a Ferengi's mother. ("The Siege")
33. It never hurts to suck up to the boss. ("Rules of Acquisition")
34. War is good for business. (?)
35. Peace is good for business. (?)
47. Don't trust a man wearing a suit better than your own. ("Rivals")
48. The bigger the smile, the sharper the knife. ("Rules of Acquisition")
57. Good customers are as rare as latinum. Treasure them. ("Armageddon Game")
59. Free advice is seldom cheap. ("Rules of Acquisition")
62. The riskier the road, the greater the profit. ("Rules of Acquisition")
75. Home is where the heart is, but the stars are made of latinum. ("Civil Defense")
76. Every once in a while, declare peace; it confuses the hell out of your enemy. ("The Homecoming")
102. Nature decays, but latinum lasts forever. ("The Jem'Hadar")
103. Sleep can interfere with [unfinished; profit, perhaps?]. ("Rules of Acquisition")
109. Dignity and an empty sack is worth the sack. ("Rivals")
111. Treat people in your debt like family... exploit them. ("Past Tense p1")
112. Never have sex with the boss's sister. ("Playing God")
139. Wives serve, brothers inherit. ("Necessary Evil")
194. It's always good business to know about new customers before they walk in your door. ("Whispers")
211. Employees are the rungs on the ladder of success... don't hesitate to step on them. (?)
214. Never begin a business negotiation on an empty stomach. ("The Maquis, Part I")
217. You can't free a fish from water. ("Past Tense p1")
239. Never be afraid to mislabel a product. ("Body Parts")
263. Never allow doubt to tarnish your lust for latinum (?)
285. No good deed ever goes unpunished. ("The Collaborator")
286. When Morn leaves, it's all over. (Not a real Rule, but one that Quark made up in "The House of Quark.")