When someone adds their own (or another person's) name to Urban Dictionary, either to flatter said person or to insult them. Urban Dictionamers don't realize that no one will read or care about these definitions. In the end, this is just extremely irritating and fills up the voting list (although I doubt the site's moderators will care enough to stop it).
A Shackteau is a humble, weather-beaten, structurally questionable shelter located in a spectacular or highly coveted place—Wales, Jackson Hole, Sun Valley, Crested Butte, coastal Maine, the Alps—where the building itself may be worth almost nothing, but the dirt, view, access, and mythology make it absurdly valuable.
In use:
Shackteâu - We thought it was an abandoned shed until the realtor called it a rare alpine Shackteâu with unobstructed views and listed it for $2 million.