Replying to a specific person's comment

I checked the FAQs to look for an answer without any luck. Forgive me if it is there and I overlooked it. I recently asked a question with the title: Causality in a gedanken experiment on the hydrogen atom, and John Rennie commented on it. In my response I simply put his name in the text. I mean it was like "Yes, John Rennie ..." instead of "@John Rennie Yes ..." I have observed that the latter is pretty standard on this forum and I would like to learn how to do that. Could someone please tell me how that is done?

Thanks.

As dmckee wrote in a comment, the full details are at this question on MSO, but I'll reproduce a rule of thumb here: all you have to do is put @ before the name, and omit the spaces. You don't need to put it at the beginning of the comment. So to reply to John Rennie you could write Yes @JohnRennie and so on.

You can also omit characters after the first three. So @Joh, @John, @JohnR, etc. all work equivalently to @JohnRennie.

• Comment to the answer(v1): But user John Rennie has a space in-between his first and last name, so it seems that three of your five examples above would not work. Or do they after all? – Qmechanic Dec 19 '12 at 9:27
• Answering my own comment: They do after all. See e.g. point 5 in this meta.SO answer. – Qmechanic Dec 19 '12 at 12:32

I saw the comment anyway because I tend to keep an eye on questions where there is an unresolved issue.

If you type @ then start typing the name you should get a little popup suggesting a name. Click on the pop-up and it will fill in the correct name. I'm not sure how these names are created: for me just omit the space so type "@JohnRennie".

BTW did you look at John Baez's article? I see you have a couple of answers, but it doesn't seem to me that either of them really address your question.

• Hi @JohnRennie, thanks for your response. FYI: I don't see the pop-up when I start typing @ + name. You are right. I did not find the post by anna v helpful. It doesn't contain anything I don't already know. Yes, I saw John Baez's article before posted my question. I am familiar with the EPR paradox and its resolution. Baez's argument sort of make sense; it falls into a category descriptions which are able to explain a specific scenario, but extremely difficult to apply to other situations, namely the hydrogen atom example. – PhHEP Dec 19 '12 at 14:02