You can manage notifications in the Comment and Change History columns options :

 Choose Manage notifications

 The Manage notifications pops up :

Visual  notification :

Match the red pills that contain the number of new items you have not seen yet :

Notification pills example : 

Here, possible options : 

• Not displaying notifications
• Displaying notifications
• Display only when an alias is mentioned
• Display only when the user ID is in a column

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