A man at the auction the other night told me that "you can tell male from female chicks by their headspots." I asked him if he meant barring (trying to get a handle on how much this guy knew, because he was selling some "sexed chicks" I wanted. I don't need males). He said no, and told me to look up black sexlinks. He then informed me that this headspot could be used to sex all chicks. I was trying to figure out what he was talking about, and asked him if he meant all chicks whose mothers had barring.
He acted like I was a bit slow for asking this twice, and proceeded to inform me that he meant all chicks, and no, it did not have anything to do with barring. He again told me to look up black sexlinks. I said yeah, that's sexlinked barring. It only works if the mother chicken is barred. He decided to discontinue the conversation.
(I'm in my twenties, but can pass for sixteen pretty easily. This guy was in his fifties. I've learned the hard way at several workplaces that some people take that as a license to be condescending, but wow.)
And the worst part is, he raises multiple species of birds, including guineas and peacocks, and he's been raising chickens for years longer than I have.