Well, darling, "ati br cn" on a necklace is most likely the chemical symbols for Astatine (At), Bromine (Br), and Carbon (C). So, unless you're a chemistry buff or just really love those elements, it's probably just a quirky accessory with no deep meaning. But hey, wear it proudly and rock that science chic look!
Ati
What does ATI BR CH mean on jewelry
What does 58 mean on a bracelet
What does 14 KGB mean on a bracelet
CN means charge nurse.
It can mean "Code Name" as in the popular Korean Band CN BLUE
.cn means, china internet addresses
RC1 means a jewlery company made the bracelet.
What does it mean if you break a yellow jelly bracelet
Depends. Could mean he likes her, could mean he just gave a girl his bracelet. I think it would depend more on what he said when he gave this girl his bracelet.
"what do you like to do?"