To many guys, there are few things as frustrating or mysterious as the oft-mentioned — and oft-derided — “girl code.” To us, it seems much too fluid and indefinite a concept, too abstract and full of loopholes to wrap our minds around. Small wonder many of us have given up on ever trying to understand it.

But what if we did try? Let us consider, for example, the issue of dating a best friend’s ex: What does girl code have to say about the subject? What kind of rules have to be followed?

At first glance, it seems to be simply an issue of consent.

“It’s not OK to date a friend’s ex unless you talk to your friend first and make sure it’s OK with her,” Jackie L., an undeclared freshman, said. “Always talk first.”

Judging by the responses of the girls interviewed, being forthright about one’s intentions seems to be a key element of girl code. However, not everyone sees it this way.

Alex Taylor, a junior biology major, said she thinks exes are best left alone.

“Never date a best friend’s ex. Ever. A best friend’s ex is always off limits, regardless of how long it’s been since they were together,” she said.

Even with the difference of opinion, all of the girls surveyed did share one common view: failing to adhere to this girl code could lead to disastrous consequences.

“I would never do it to my friends, and I’d be incredibly angry if they did it to me,” Jackie L. said. “It can definitely ruin friendships.”

Taylor agreed. “I would feel completely betrayed if one of my best friends started dating my ex. I have seen numerous friendships ruined because girl code is broken.”

According to the girls, this is a key difference between girls and guys — the severity of the consequences.

“I don’t think this idea is shared by guys,” Taylor said. “Usually guys will ask their friend if they’re alright with it, and then pursue their ex. It’s definitely simpler, and not as strict.”

The rules also seem to apply to casual hookups, too, which the girls say are not OK.

Exactly what else is “OK,” however, is a nebulous concept, especially for guys, for whom there is perhaps no hope of ever fully understanding the rules of the elusive girl code.

“Give it up,” Jackie L. said. “It’s a girl thing.”

So there you have it: girl code. It’s a strange concept — but to girls, it all makes some sort of sick, twisted sense.

Editor’s note (6/18/23): This article has been edited to better reflect the name of one of the interviewees, Jackie L.