The Federation Uniform Mercantile Code, or FUMC, was a set of laws regulating mercantile activity in the United Federation of Planets and those traded and held treaties with.
The FUMC became law on reference stardate 1/4212.31 (c. 2217), despite Orion protests. Its terms would force their homeworld of Botchok and the Orion Colonies to abide by the laws or face prosecution. However, the Rigellians applied for an exemption due to cultural tradition, and were successful.
On stardate 1/4705.18 (c. 2219), a Federation Tribunal found the Orion Duraba Corporation guilty of 1850 separate violations of the FUMC in a criminal conspiracy across 20 planets. This resulted in anti-Federation riots across the Colonies that took over 6000 lives and cost 37 million credits in damages. (FASA RPG module: The Orions: Book of Common Knowledge)
To promote trade in struggling areas and industries, Federation trade policy allowed for certain exemptions to the FUMC. Under these allowances, Orions formed freeports, exempt from taxation, duties and licensing fees and other strictures of the FUMC. (FASA RPG module: The Orions: Book of Deep Knowledge) Freeloader, the most infamous and successful of the Orion freeports, was officially opened in the Triangle on stardate 1/5103.27 (c. 2222).
The restrictions of the FUMC slowed Orion economic growth such that it could not recover from earlier setbacks. This state of affairs persisted until the outbreak of the Four Years War between the Federation and the Klingon Empire on stardate 1/9409.29 (c. 2250s). The Orions had eagerly awaited the opportunity to profit off both sides, but were surprised when the Federation forbade them from trading with the Klingons during the war, according to the terms of their treaty and the FUMC. Forced to choose between the two powers, the BPC complied, though several Orion businesses were bankrupted; the Federation was blamed, rather than the BPC. As a result, several Colonies in the Triangle declared independence from the BPC in stardate 1/9412 and formed the Orion Frontier Mercantile Association (OFMA), and continued trade with both sides. Many others followed, and the Federation–BPC agreements became worthless. (FASA RPG module: The Orions: Book of Common Knowledge)