This userbox declares that the user has a "committed identity" and optionally links to a user subpage that contains the identity hash. See the documentation for Template:User committed identity for more information on creating a committed identity.
subpage: If you use the optional subpage parameter, then the word 'unique' will be linked to a user subpage with the name you specify. For example, if the user named "ExampleUser" placed the box on their user page or user talk page like this:
Then the word 'unique' would include a link to the page "User:ExampleUser/Identity".
The linked page is always a subpage of the main user page, regardless of whether the box is placed on the main user page or the user talk page. If the target page does not exist, then the link will not be created. The linking will not work correctly if the box is placed on a page outside the User namespace.
background: The background parameter allows you to set a background color for the box. If you do not specify a color, it defaults to the color code #FFFFCC (an off-white color like this). See w:Web colors#Hex triplet for more information on color codes.
border: The border parameter allows you to set a color for the border of the box. If you do not specify a color, it defaults to "#FFCC00", a golden color.
- Template:User committed identity - used to place the hash on your user page
- w:User:Urdna/CIDuserbox - inspiration for this template, but the styling and subpage link name are hardcoded
- w:User:Anomie/Userbox committed identity - another userbox; includes an option to declare that you do not have a committed identity