when you use the Reply at the bottom of the post you just read, your reply is connected to that post. so if you went to Settings/General Settings and chose threaded under Thread Display Mode:, you will see how the replies are associated with the post. in our forums, most folks don't use that view. but if you used that view and used the Reply at the bottom of a later post, you will see that your reply is connected with that particular post. most, however, use Reply with Quote when referring to another post in the thread so it is clear what you are replying to. it is not wrong to use the Reply to Thread or to scroll to the end of the thread to use the Quick Reply box.