__Authentication__: All of the self-service examples require some kind of authentication/identification for the person using the form. There are variations in how this is done, e.g.
* Username/password (i.e. log into Drupal with a username and password, authenticating as the correlated contact)
* Email with link (i.e. send an email via CiviMail, CiviEvent notification, et al with an authenticated link
* Email with link (i.e. send an email via CiviMail, CiviEvent notification, et al with an authenticated link)
* Access code (i.e. begin a multi-step pageflow; as a step in the process, send a confirmation code over email or SMS - then continue with the flow)
__Minimum access/Privilege escalation__: Self-service forms are less categorical than backend or public forms, e.g.
