Costal stigma, also known as the rib mark, is a term used to describe a visible indentation or line that forms along the side of the body where the ribcage is located. Although not commonly referred to using synonyms, there are a few alternative ways to describe this characteristic. One could say it is a rib crease, rib groove, or even a rib furrow. These terms highlight the presence of the indented line that appears along the sides of the torso where the ribs lie. Regardless of the terminology used, the costal stigma is a natural anatomical feature, and its visibility may vary in individuals based on factors such as body composition and posture.