Sometimes in email he will use my first and last initials instead of my first name. I don't think I'd like it if he did that all the time, but when he does do it, it feels personal in an okay way. If, however, he took my first name and shortened it, I wouldn't be okay with that because I don't like to be called that. That seems like something that you need to give permission for. If you don't like or want to be called that, just tell her you don't like it. I doubt most people would take offense and would be glad to know.

My neighbor, who I can't stand, used to call me by the shortened version of my name and one day I'd had enough and just asked "why do you keep calling me that, that's not my name". I'm still not sure how they got the impression that's what I went by, but it sure felt good to get her to stop calling me that.