Most likely you already know mentions from social sites such as Facebook or Instagram. In Freelo it works the same way.
In a comment you can mention another user when using @UsersName and he/she gets one time notification. There is no need to assign the task to someone. Just notify the user that you need a one time reaction.
How to mention a user
In the text editor in a discussion type “@“ and start typing the user’s name. The user will appear in the list of users and you must select them.
In case you mention a user or all project members, they receive one time notification automatically. In Freelo the notification center shows the alert Mentioned you.