How to Avoid Copyright Violations

I think especially when I said I did not understand copyright. And at first I had a few up and then I got dinged for all of them. Like back then I was like, I'm not really using the word. So like it's fine. But if you're using someone else's success to profit off of, then it's probably way counting towards like a trademark. Can you give me an example? Would you be willing to share one text that you use that was like, Oh, this is skating the line?"