Want someone to see a post or comment you made? Use a mention.
To mention someone, type the @ symbol directly before the username of the person. Do not put spaces between the @ symbol and the user name. It should like like this: @sotrender. The person that you mention will receive a notification in his Activity tab.
You can mention someone in both posts and comments. If you use Instagram on the iPhone or iPad, press and hold any comment thread to start commenting and include a mention.