This template converts a diff URL to use the {{diff}} template. Diff URLs must be from the host "en.wikipedia.org", and they must contain one of the query strings |title=, |diff= or |oldid=. In other words, they must be of the format en.wikipedia.org/w/index.php?query. URLs of the format en.wikipedia.orgview_html.php?sq=&lang=&q=Page name will not work.