If you want to make sure that a person sees a comment you are making to them anywhere other than on their own item for sale, you need to tag them. Most people have settings where they get notifications if you write a comment on one of their own items, but sometimes you would like to put a comment pertaining to the item that you sold, and then you would want to tag them on that item. For example, if you are saying that you will not be sending the original box with the sold item, so that this information is documented under your sold listing in case they have a complaint about it later.thanks...in my case I put the question on the sellers listing and she answered but that's not always the case