Badges are small, simple components for displaying an indicator or count of some sort. They’re commonly found in email clients like Mail.app or on mobile apps for push notifications.
The badges is a good idea to show status and be notifiers. Change the shape to also go with the context of notification and to give more cues to the severity level if it is to show status or waring. Numbers are one of the sets of glyphs that can be incorporated. Punctuation and commonly used like "i' and " !", other known like shapes triangles