Wikipedia:USERBOX

The first userboxes were introduced to support the Babel inter-language effort by indicating users' skills in other languages.

Userboxes belong on their users' pages. In some cases, it may be considered uncivil to place userboxes on other users' pages without their permission (especially in a mean-spirited way—homophobia, racism, sexism, etc). However, userboxes may be placed on non-mainspace talk/discussion pages by anyone. (See also .) The {{}} template can be placed after the plain userbox if text is added on a new line immediately after it.

A gallery of existing userboxes can be found here: WP:Userboxes/Gallery.

The standard syntax for adding a userbox to your user page (also known as transclusion) is: {{user name_of_box}}.

You may decide to substitute the template code onto your user page using the syntax {{subst:user name_of_box}}. The use of "subst:" will ensure that the template is always displayed in its form when you add it to your user page, i.e. it will not reflect subsequent edits to the template. This method will lead to large amounts of code on your user page.

If you have designed a userbox that you would like to make available to others, you may wish to first display it on the for community comment.

Userboxes may only be created or displayed in the User, Project, or Template namespaces.

So should your userbox be prefixed with User:, , or Template:?

If in doubt, consider presenting the userbox at for community comment.

Please be mindful of the colour contrast guidelines at WP:COLOUR - low-contrast colours present accessibility barriers to people with colour-blindness or other visual disabilities.

...
Wikipedia