Help with People, Dropboxes and so on
Let's explain this with an example. John wants his colleagues Fred and Jan to assign tasks to him. John logs in to Undone, and clicks add a person on his people page. He types in Fred's email address and some tags that let him know when an action has been added by Fred: he decides on fred, work, support calls. He defines which projects Fred can add actions to. John goes on to add Jan.
Fred creates an account on Undone using the email address that John supplied, and John has appeared in Fred's sidebar as a person Fred can drop actions on! Now all Fred has to do is visit John's dropbox and he can add actions. Actions he adds to John are tagged as per John's settings, and Fred only has access to projects that John has allowed. If the projects are configured for Fred, but are also hidden by John, Fred can still add actions t othem but will be unable to see the actions he adds.
Jan logs in and decides she doesn't want to drp actions on John, so she visits her own people page and clicks on decline next to John's name. John disappears from Jan's list.