Non-existent anchors are marked with [Invalid]. These redirects can be retargeted to the correct section or by adding an anchor to the page (e.g.
== Other related media <span id="Video games"></span>==). Incorrect redirects are sometimes caused by bots fixing double redirects.
Formalization is somewhat similar
Viewing 23 redirects334 anchor found in Algorithm of which 151 were not produced by cite.php