The cipher is also known as the tic-tac-toe cipher and is a geometric substitution cypher where letters are substituted for symbols which are fragments of a grid. It is also known as The Freemason's Cipher - Freemasons have been known to use ciphers since at least the 18th century.
A simple one is
Can you decipher this message?
To explore this cipher further visit The Pigpen Cipher Encoder on the Village Interweb.