You can reply publicly to any update on oGoing by using the @username format. Just type in an update such as: @username (my update) and this update will be shown on your profile page, and also sent to the username's profile page. Thus, an @reply is a public message sent from one person to another. How is the reply update different? If a message begins with @username, it is shown as a reply. You can also go to someone's update on your home page, and click on the Reply button to send a reply to that person. You don't need to follow someone to send a reply, and all of your replies are visible in the @username tab in your home page sidebar. Updates starting with @username are replies, and Updates with @username elsewhere are considered mentions. Please note that if your account is private, users who are not following you will not see your @replies or mentions.