@Mentions
The @mention functionality is available to review participants both in global comments under the General tab and under Annotation in the review comments.

You can mention other users in comments by typing @ in a comment and then the user name. The mentioned user will automatically be notified of the mention by e-mail or in the application under the bell icon. The user can then switch directly from the notification to the review and to the comment.
The @ sign first suggests the participants of the review. If your role has the appropriate authorization, you can also invite other users to participate in the review. You can only invite users who are authorized to access reviews.
Users who were not previously invited to participate but are mentioned in a review with @ are automatically added to the review as new participants with the role of reviewer. If a mentioned user is already a participant in the review, their existing role in the review remains untouched. A guest always remains a guest and owners do not become reviewers.

The logged-in user is currently writing a global comment as the owner of the review and would like to mention another user Notburga Neidhart and thus invite her to participate in the review.
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Type @ in the comment field and then enter the first letters of the name.
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Click on the user you are looking for in the list.
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Send your comment by clicking on the paper plane icon.
After entering the first three letters, the Invite user list will be displayed.
You have mentioned the user Notburga with @ and at the same time added her as a participant in the review.