Deaton has a collection of jars that bear symbols. So far, these are the ones we've been able to see.
This symbol stands for protection. It is often associated with the Celts, but goes back to Mesopotamia. The four corners are a call to the gods of the four corners of the earth. In Kabbalah, it is the symbol of the Shema and invokes the four Archangels.
Or triquetra. Celtic symbol of the Goddess. In Wicca, it is taken as maid, mother, crone. It can also mean mind, body, soul, or earth, sea, and sky.
Literally poetic inspriation or spiritual illumination. The left bar represent the male, the right bar the female, and the center bar the balance between the two.
Represents the solar calendar, with the spokes marking solstices and equinoxes.
The symbol in general can mean many things: past, present, future; mother, father child; or alpha, beta, omega. For werewovles, it symbolizes that possibility that any wolf can rise or fall to any status. A beta can become an alpha. An alpha can fall all the way to an omega.
The revenge spiral is a simple spiral consisting of any number of revolutions. It signifies that there is a blood debt to be paid. Derek buried Laura under a spiral of rope attached to wolfsbane, which kept her from shifting and signified his intent to kill whoever killed her. Peter Hale drew the spiral in a number of places to signify that he was meting out justice to those who killed his family.
+Ogham Symbol - Luis
The symbol that Deaton has written on his mountain ash jar is luis, from the ogham alphabet, which is the symbol for the rowan tree, also called quicken or mountain ash. Rowan is used for protection against magic and enchantment.