Pigpen Cipher

 The Pigpen Cipher was created by the Freemasons so they could keep documents safe. It was also used by the confederate soldiers during the Civil War. It is called The Pigpen Cipher because the box's look like pigpens and the dots look like pigs. It seems complicated but it isn't really. The lines surrounding the letter and the dots within those lines are the symbols.
There are a few variations of the grid but they all use the same concept.