Manual:$wgUseTrackbacks

Details
$wgUseTrackbacks enables blog-style [http://www.sixapart.com/pronet/docs/trackback_spec trackback] support if set to true in . When MediaWiki receives a trackback ping, a box will show up at the bottom of the article containing a link to the originating page. The link format can be customized by editing MediaWiki:Trackbackexcerpt.

However, MediaWiki does not support sending trackback pings.