News came out over the weekend that Derek Jeter will end his status as baseball’s most eligible bachelor. The Yankees shortstop will wed actress Minka Kelly on Nov. 5, according to Newsday.

Jeter might be a newby to the wedding game, but he won’t be blindsided when it comes to monitoring his wife’s interactions with his teammates. This is part of the clubhouse code, in which players protect each other from forces outside the clubhouse: management, media . . . and women.

The rule in question is designed to keep the worlds of wives and girlfriends at a safe distance, especially among players who have a toe in each pool. It’s the basis for wives and girlfriends having their own seating sections in a given ballpark, the better to reduce chances that they’ll inadvertently run into each other.

This isn’t to say that Jeter will be anything but faithful, but at the very least he’ll know enough to protect teammates who might not measure up to that standard. It is, after all, an unwritten rule.

The following excerpt from The Baseball Codes has more.

For ballplayers, protecting teammates from the women in their lives can be complex, especially when it comes to possible trysts on the road. The crux of the problem with this particular endeavor is that it involves ballplayers—the most visible people in virtually any public environment—trying to stay as invisible as possible. The bond between players is strong, however, and they do what they can to maintain each others’ anonymity.

It’s why players whose wives show up during road trips make clear to their teammates where on the town they’ll be that night, to avoid the chance of running into a married player on a “date” with someone other than his wife. (Mets pitcher Doug Sisk was once guilty of this when he brought his wife Lisa to the team’s hotel bar, where she saw a number of his married teammates getting friendly with strange ladies.)

This is why some players implement an ignorance rule at home. “My policy with my wife is this: don’t ask me,” said one longtime pitcher who vowed fidelity but didn’t want to incriminate his teammates. “First of all, I don’t want to lie to you. Second of all, I don’t want to tell you that this guy’s cheating on his wife. You’re her friend, you’re going to be sitting next to her at games, your heart will be breaking for her—you can’t do it. Please, just don’t ask me. Don’t ask me, because I don’t want to put you in that situation.”

Not everybody is so virtuous. Players have been known to prattle to their wives about the extra-marital adventures of their teammates in an effort to mask their own infidelities. Wives inevitably talk to each other, and when word gets out about where it all started, clubhouses can fracture. When a player is inexplicably traded over the off-season for less than full value, there’s a reasonable chance that he betrayed his teammates in this or another regard (or, in turn, that he was betrayed by a less-expendable star).

The best story we found on this topic was told by Negro Leagues star Buck O’Neil. But we don’t want to give too much away here. You’ll have to wait for that one until the book comes out.

– Jason