Answer
- Click on "Add as collaborator" next to the name on your "Friend list" that you want to add to the project as a Project collaborator.
- In the popup window, uncheck the "Send notification" box, click ü, and then "x" to close the window.
- Refresh the browser (go to "View" and click "Refresh" or "Reload"). You will now see the name added to the list of Project collaborators.
You can see that adding a user to your "Friend list" is a smart way to expedite adding her/him to a Project in the future. Click here to find out how.