Rock Sign?

Depends on the culture. It’s actually called the corna, or sign of the horns. In Mediterranean countries it’s seen with a negative connotation, for instance, in Italy. If the horns are behind a person’s head and pointed at an individual, it means they’re guilty of infidelity.

But the supposed origin is said to date all the way back to Greece, as a sign of the minotaur who was an illigitimate child of a queen and a white bull. Which supports the idea of betrayal, or infidelity seen in other countries.

However, in Cuba the same sign is a joke, when posed behind someone’s head.

Anton LaVey used it as a sign for satanism.

In baseball it’s used to signal two outs, and in football it’s used to symbolize the second down. Additionally, the Texas Longhorns use the sign along with their phrase “hook ‘em horns!”

So really, the meaning is dependent on the individual and the culture that individual is in. You get to decide what it means.