Comment by WalterBright

Take a look at Fig 1. A grid of dots. A sequence of X's. Does it mean "Property of Thag?" "Happy Birthday, Mom"? Are the X's there to improve one's grip on the object? Are they just idle doodling around the campfire? Hunter-gatherers have little use for writing.

We'll never know.

When I was young I was fascinated by drawing 5 pointed stars. It meant nothing.