Shows a link if the page linked to exists, doesn't if it doesn't.

{{LinkIfExists|Main Page}}
Main Page
{{LinkIfExists|WP:RFD|Delete a page!}}
Delete a page!
{{LinkIfExists|The Weather in London}}
A passport is needed when you visit {{LinkIfExists|SlugNation|here}}.
A passport is needed when you visit .
change

{{autolink}} {{greylink}}