The official app for iPhone and iPad is where you can learn how to mention a user.Mentioning a user like this makes them aware that they were mentioned in a post.
Step 1: The app is open.
There is an orange app with a white cartoon alien.If you don't have the app, you can sign in with your account from the App Store.
Step 2: You can start a new text post or comment.
To post a comment, tap below the post you want to comment on.To start a new text post, simply tap and select from the menu.
Step 3: To follow the person's usernames, type /u/.
You would typeRandomUsername in your text if you wanted to link to it.
Step 4: If you want to send a post, tap it.
It is in the upper-right corner.The user is mentioned in your text on the site.