Client: Can you change the phone number?
Me: Of course. What number would you like it changed to?
Client: I don’t want the actual number changed, I just want it in lower case.
Me: I’m not sure I understand. Numbers don’t have an upper or lower case. They’re just numbers.
Client: It doesn’t look right. Just make them lower case and get back to me when it’s done.
The client hung up. I continued the work and pretended that conversation never happened. He never mentioned it again after that.