Participants with the Viewer role in a discussion are not able to comment on claims directly. Comments from Viewers are submitted as suggestions for Admins to review and accept.
Once a suggested comment is accepted, it appears for all users in the discussion as a regular comment.
Admins can also respond to suggested comments, for example, if they feel it needs further clarification. Once an Admin responds, the author of the suggested comment receives a notification and can edit and resubmit the comment.
If you mention another participant in a suggested comment who isn’t an Admin, they’ll receive a notification and be able to view the comment once an Admin accepts it.