The addition of new weight classes in mixed martial arts has been discussed for years and the discussions began heating up late in 2015.

On Wednesday, they were finally codified in the Unified Rules of MMA by the Association of Boxing Commissions and Combative Sports (ABC) at the organization’s annual conference in Connecticut. The vote was unanimous.

The ABC approved the addition of four new weight classes — at 165 pounds, 175 pounds, 195 pounds and 225 pounds, per multiple regulators in attendance at the conference. The weight classes will be called super lightweight, super welterweight, super middleweight and cruiserweight, respectively. The current 170-pound division — welterweight — will remain in the Unified Rules.

The new weight classes were approved after being brought to the ABC body by the MMA rules and regulations committee and California State Athletic Commission (CSAC) executive officer Andy Foster, who had the four new divisions as part of his 10-point weight-cutting plan.

The rules and regulations committee passed the new weight classes last year, but there wasn’t enough support for them in other committees and a vote never reached the ABC body.

It’s important to note that promotions have no obligation to adopt any of these weight classes, much like the UFC has not brought in women’s flyweight or featherweight until recently and Bellator has no flyweight division.

“Just because cruiserweight now exists doesn’t mean that the UFC or Bellator or anybody else has to put in a cruiserweight division,” said Sean Wheelock, the chairman of the rules and regulations committee. “MMA promotions run their own belts — you can do a title at a 162.2 pounds if you want.”

Foster, though, believes that eventually the big promotions will adopt the new weight classes, once they begin being used at the amateur and regional levels.

“When California club shows and Texas club shows and others have 165- and 175-pound divisions and fighters are locked into those, then I think we’ll see a change,” Foster said. “It could take four or five years, maybe shorter than that.”