Diligence is still under development and incomplete, and some this documentation is wrong.
For a more comprehensive but experimental version download the Savory Framework,
which was the preview release of Diligence.
This complement to the authentication service
uses a two-step process to allow new users to register to your application. As is common, it expects users to have a personal email address, which will be used to both confirm the identity of the user and to communicate with the user when they are not logged in.
The feature contains a /web/fragment/ HTML form with a CAPTCHA, which collects the user's email, username, password and possibly some personal information. The form will be valid only of the username is not already in use.
If the form is valid, the user is created but not yet activated. An email is sent to the user with a unique, impossible-to-guess URL, which can be used only once. If they click on that link, the user is activated.
The feature allows for not-yet-activated users to be automatically deleted after a certain time. This would release the username for others to use.
The Diligence Manual is provided for you under the terms of the Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International License.
The complete manual is available for download as a PDF.