the C stands for “Crap”, that more or less is the ultimate nature of all the coins in the crypto-world, but this ecosystem is complex so you could forget you are investing on toxic titles backed on nothing so the almighty Do Kwon put a C on luna, so you will remember you are buying his crap and next time you will lose money for his idiocy/malice (choose the option you like,it makes no difference) you are less prone to go snivel