These are example Activity object which can appear in the Activity feed or can be escalated to Notifications
[USER] submitted a change to [PAGE]. View diff, approve or reject?
[USER] followed you
[USER] followed your page [PAGE]
[USER] requested to join your group [GROUP_NAME]
[USER] pledged their support to [PAGE] at $2.10/mo
[USER] merged pages [PAGE] and [PAGE]
[PAGE] backlinked to [PAGE] (you’re following the latter)
[USER] renamed page [PAGE] to [PAGE]
[USER] quoted you on [PAGE]
Congrats! You have an X day long Streaks for your daily notes or contributing to [GROUP]