Mention a user or channel in Chat (App)
This article explains how to mention a user or channel in Chat.
Steps
Select the channel or direct message where you want to mention a user or channel.
2. Type @ in the messaging field followed by a specific user's name, or the word channel.
As you begin typing, the names of the users in the channel or direct message and/or the @channel option will populate (depending on what you type). The option that most closely matches what you are typing will be highlighted in blue. You can press Return/Enter to autofill the option that is highlighted.
3. Type your message after the mention.
4. Press Enter/Return.
Read more
Change notification settings for channels and direct messages in Chat (App)
Overview: Mentions in Chat (App)