In the “Comments” tab you can view and write comments concerning the item. You can also make replies to existing comments.
Make Comments to Specific Users or Teams
If you want to be sure, that specific users or the users of a team are reading your comment, you can mention the user or team in you comment. Write “@” in your comment followed by the user or team name.
As soon as you write @, a popup list with users and teams will appear. Select the user or team, you want to address.
Read more about editing comments here.
How does the User see his Unread Comments?
The user will now see a wide button in the activity logs, to inform him, that he must read and confirm the comment.
In addition to this, a digest mail to the user will include his unread comments. The frequency of digest mails depends on the system setup. I.e. whether it is send once a day, once an hour or with some other time interval. The digest mail is only send, if there are new comments or assignments made after the previous digest mail.