From the Wheel of Time series, an action that comprises saying Shai'tan, the true name of the Dark One. Merely saying his name brings his attention upon you and allows him to touch the world. His followers are also careful not to say his name, claiming that doing so would be blasphemy.

From the Glossary of The Wheel of Time

Saying the true name of the Dark One (Shai'tan) draws his attention, inevitably bringing ill fortune at best, disaster at worst. For that reason many euphemisms are used, among them the Dark One, Father of Lies, Sightblinder, Lord of the Grave, Shepherd of the Night, Heartsbane, Heartfang, Grassburner, and Leaf-Blighter. Someone who seems to be inviting ill fortune is often said to be "naming the Dark One."

In the illustrious game of NetHack, I suppose this would be when you use the "call" feature of the game to name the Dark One (the Wizard quest nemesis) something besides "the Dark One". I guess you could do that just for kicks, or maybe to make amusing messages. Whatever floats your boat.