When the bumps of the spine are visibly beneath the skin on the back. Eg, post #5470255. Often seen in cases of extreme thinness. Not to be confused with a simple line to indicate the spine eg, post #6218597. This also does not apply to character designs with a transparent body and a visible skeleton beneath it or character designs with spines on the outside/sticking through the skin eg, post #6844681 post #6982123. This tag applies specifically to individual bumps visible underneath non-transparent skin.