Define “Naughty” Black Mug, 15oz

There is clearly a lot of gray area when it comes to Santa's list! Some clarity could be helpful!
These black mugs come in one size – 15oz (0.44l) – plenty for morning caffeine boosts and hot cups of tea on a rainy day. They're easy to grip and feel sturdy thanks to the C-shaped handle. 
.: Black ceramic material with a glossy finish
.: One size: 15oz (0.44 l)
.: C-shaped easy-grip handle
.: Lead and BPA-free