Why do the ninjas have these symbols?

These symbols are featured on many of their suits and I can’t figure out why. Why initial thought was it was their element in ninjargon but it’s not. I looked into them and they are actually characters from the font fusaka and have nothing to do with their name or powers! For example the one that appears on Kai is an I which has nothing to do with anything! So if you know anything about these symbols and why the ninja used them I would love to know For those curious jays is a Y, Cole’s is a...