Manual:$wgAjaxExportList

Details
Registry for functions callable via Ajax. This is a way for extensions (and some functions) to make functions callable from JavaScript (extensions acting as Ajax callbacks must register here).

Properly marked as deprecated [https://gerrit.wikimedia.org/r/#/c/262460/ in 1.27].

 and  cause  and   to be added to this array, respectively. See also .