Template:Whatlinkshere
[[Special:Whatlinkshere/Template:{{{1}}}|{{{1}}}]]
First parameter is the page being linked. (i.e., {{Whatlinkshere|fact}} links to Special:Whatlinkshere/Template:fact.)
Optional second parameter can change the text displayed. (i.e., {{Whatlinkshere|fact|What links to "fact"}} yields What links to "fact".)
Optional |namespace= can be used to specify links to pages outside of the Template: namespace.