The Ferengi Trade By-Laws are the codified code of conduct for Ferengi engaging in commerce within the Ferengi Alliance and, to an unknown extent, with other species.
Unlike the Rules of Acquisition, the By-Laws are very much a legal code. While the Rules are intended to be a philosophical guide to the acquisition of wealth, the By-Laws regulate commerce through strict rules on taxes and trade, as well as ensuring that all business conducted by Ferengi adhere to traditional cultural values. The By-Laws prohibit the forming of unions and any form of commerce with Ferengi females, among other things. However, there is apparently no prohibition trade with non-Ferengi females. (DS9: "Bar Association", "Family Business", "Ferengi Love Songs")
The By-Laws are strictly enforced by the Liquidators, agents of the Ferengi Commerce Authority. Violation of these laws can result in severe fines, or even the revoking of a Ferengi's rights to conduct business with anyone associated with the Alliance.
Section 105, Sub-Paragraph 10 of the By-Laws pertains to the Ferengi Attainment Ceremony and states that upon reaching adulthood male Ferengi must purchase an apprenticeship from a suitable role model. (DS9: "Heart of Stone")
Sub-section 1027, Paragraph 3 of the By-Laws defines the obligation of a Ferengi regarding oversight and supervision of family members.