I think I've found my answer.
Certified Zombie Hunter
By the way, an adult asking a teen about something does not always get an honest answer.
Not that I don't trust my grandson, I just wanted an independent review of what the symbol might be.
Just in case it was something his mother should be concerned about.
Ask him. Maybe it's something silly, maybe it's something meaningful to him. It's probably something benign. There's also the chance that he simply saw it somewhere and decided to adopt it without recognizing the meaning (if any) of it.
Well it’s either to not confuse the letter z with the number 7 or he’s a member of the polish secret police.
But seriously if he keeps it there or starts writing it on multiple personal items then get with the school and see if it’s a marking for a certain group or wannabe gang.
It's a 'Z', with a stroke: [en.wikipedia.org]
Interesting. I've had a fascination with things European throughout my life. I often wrote a capital Z with a stroke because I saw it used in European text and just liked it. I also write seven with a stroke for same reason. I never realized it had so many varied associations. I did know about its mathematical association.