When someone makes a comment on a project, any project collaborator who has their default notifications set to on will get an email that a comment was made that will include the text of that comment.
If the person making the comment wants to send a notification for specific project collaborators, they can mention them by typing an “@” symbol and selecting the people they’d like to notify. This will send an email notification directed at the collaborators mentioned. When a user starts to type an “@” symbol inside a comment, they will get a list of all the project collaborators to select which ones they want to mention.