With a Supreme Court ruling issued on Wednesday, Mexico has crossed an important technical hurdle towards establishing marriage equality throughout all of its 31 states.

The Supreme Court and several lower courts have already ruled in almost every state that same-sex couples have the right to marry under the Mexican constitution. But because of the Mexican court system's often confusing technicalities, none of those decisions have been binding in future cases. Theoretically, any court could rule against a couple who has sued for the right to marry even though there have been many cases decided in favor of others couples.

That is no longer true. On Wednesday, Mexico's Supreme Court issued the first blanket statement that laws prohibiting same-sex couples from marrying are unconstitutional in every state — what is known as "generic jurisprudence." The opinion is not yet public, but Supreme Court clerk Geraldina Gonzalez de la Vega — who worked on one of the early marriage equality suits before joining the court — wrote about the unpublished opinion in a blog post. (Decisions like these are ordinarily published within a week of when they are decided by the court.)

"The law of whatever federal entity that, on the one hand, considers the goal of marriage is procreation and/or defines marriage as celebrating the union of a man and a woman is unconstitutional," held a Supreme Court panel in response to a suit out of the state of Colima, according to Gonzalez.

This is not the first time the court had resolved a case with that exact sentence. But Colima is the fifth state in which the court had used this language, and five is a magic number in the Mexican system. Along with rulings from Oaxaca, Baja California, Sinaloa, and the State of México, the Colima ruling forms a new "generic jurisprudence" binding on judges issuing rulings in all the states of Mexico.

This doesn't mean that the fight for marriage equality in Mexico is over, however. Even with this ruling, same-sex couples won't be able to count on getting married through a simple visit to the local registrar's office. Some registrars are already granting marriage licenses to same-sex couples based on the court rulings — and this week's ruling insulates them from being punished for doing that. But registrars don't have to follow this ruling; it is only binding on judges.

It will still take a lot more cases before same-sex couples can marry as easily as straight couples can in Mexico; federal judges must rule five times in each state to create precedent that would lead to full nullification of a local marriage code. And it's not entirely clear how this process ends, Gonzalez told BuzzFeed News, because this marriage cases still making their way through the legal system are doing so under reforms enacted in 2011 that have never been fully tested.

"We're playing in a new court," Gonzalez said.