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 in 1.27.

ajaxSearch>Special:MyLanguage/Manual:$wgAjaxSearch|$wgAjaxSearch and ajaxWatch>Special:MyLanguage/Manual:$wgAjaxWatch|$wgAjaxWatch cause  and   to be added to this array, respectively. See also useAjax>Special:MyLanguage/Manual:$wgUseAjax|$wgUseAjax.