Note: Make sure you are logged in and in the correct event
If you have previously enabled changes alert in the event, some of the participants in the participant list will be yellow. These participants are highlighted to notify you that:
1. Changes are made to this participant's registration/travel details (after you enabled the changes alert)
2. You have not yet acknowledged the changes
Those changes you can also see in the quick reports in the participant overview. Registration changes in this case.
You can confirm that you have seen the changes and acknowledge them.
Acknowledging a single participant
Acknowledging multiple participants at once