This video talks through tagging people in comments and annotations:

To tag someone in a Pod you must first be viewing the Pod in 'Live mode'.

This can be reached via the link that you share with Pod viewers, or by clicking the 'Live mode' button at the top right of the edit screen.

In Live Mode, click the 'Comment' button to start posting comments and tagging people into the Pod;

You can tag people in comments, annotated parts of the Pod, and set them tasks

To tag someone, type @ and select the Pod viewer you want to tag, if their name isn't there, type @ and then their email address and they'll receive an email to collaborate.

You can also tag people via the 'Tag a user' button;