In most cases, {{Selfref}} is used to create a disambiguation link to a page in the "Wikipedia:" namespace from article-space; for instance, the page Objectivity (disambiguation) could have a self-referential "hatnote" link at the top: {{Selfref|For Wikipedia's policy on avoiding bias, see [[Wikipedia:Neutral point of view]].}}.
When using {{Selfref}} in this way, use the following format:
{{Selfref|The self-referential notice to display, including links.}}
which produces:
The self-referential notice to display, including links.
When using {{Selfref}} in this way, the text will be indented slightly, italicized (Wikipedia house style for self-referential notes), and both preceded and followed by a linebreak.
To use it inline without the indentation and line breaking, add the parameter |inline:
{{Selfref|the self-referential text to display, including links|inline}}
{{Selfref inline|the self-referential text to display, including links}}
both of which produce:
the self-referential text to display, including links (illustrated here on the same line as other content).
Unprintworthy content
Rarely, there is other, non-self-referential content which shouldn't appear in mirrors, print editions, or other off-Wikipedia reuses of Wikipedia content, and which shouldn't be italicized as a self-reference.
It is preferable to mark such unprintworthy content with the {{Unprintworthy inline}} template (which includes the noprint CSS class, but not the plainlinks class, since links in such content will not be internal self-references). Although not all mirror sites do so, the content in question can be removed by reusers of WP content, without any reformatting, by ignoring or removing content marked up by this template, or more accurately by the selfreference CSS class that it (and some other templates) use.
A "brittle", legacy usage of {{Selfref}} has technically also been used for such unprintworthy cases, and pre-dates the {{Unprintworthy inline}} template. This is to simply end the template with a pipe character – |:
{{Selfref|the unprintworthy text to display without self-ref styling|}}
This method cannot be depended upon (for one thing, many editors will interpret the pipe as an error and remove it, turning the template into an indented self-ref hatnote!). This syntax has been obsolete since 2008, and any remaining uses of it should be replaced with {{Selfref inline}} (if real self-references) or {{Unprintworthy inline}} (if simply unprintworthy).
Example
Code
Page on Wikipedia
Page on [some] mirrors
{{Selfref|For the Wikipedia Sandbox, see [[WP:SAND]]}}
The Wikipedia Sandbox is a page on Wikipedia. {{Selfref|(You can edit it by clicking "edit" on the page.)|inline}} It has been edited many times.
{{srlink}}, for the opposite case when you want a link to the Wikipedia: namespace that does show in mirrors without breaking (for instance when writing an article about Wikipedia or something connected to it).