Can refer to a scratch or a small mark on a surface.
La risca en su brazo le recordó que siempre debe tener cuidado al trabajar con herramientas afiladas.
The scratch on his arm reminded him that he always needs to be careful when working with sharp tools.
La risca en su brazo le recordaba el accidente que había sufrido años atrás.
The scratch on his arm reminded him of the accident he had suffered years ago.