Writing used in ancient Mesopotamia, which consists of nail-shaped linear elements from which the separate signs are constructed. Goes back to 2500 A.D. when the originally signs were systemized in such a way that they could be depicted with straight lines ('nails') and triangles ("nail heads"). Thus, the oldest writings are pictographic: a simple drawing of an object.

The invention of writing is being contributed to the Sumerians, but there is no absolute certainty about that.