Возможно, этот код документирован.

//compatibility for all scripts expecting Monobook-like page structure 
document._realGEBI = document.getElementById
document.getElementById = function(id){
 var x = this._realGEBI(id)
 if (x) return x
 switch(id) {
   case 'content': return this._realGEBI('mw_content')
   case 'column-content': return this._realGEBI('mw_contentwrapper')
   case 'bodyContent': return this._realGEBI('mw_contentholder')
   case 'column-one': return this._realGEBI('mw_portlets')
   case 'globalWrapper': return this._realGEBI('mw_main')
   default: return null
 }
}
/**
 * Слежение и статистика посещений
 */
var _paq = window._paq = window._paq || [];
/* tracker methods like "setCustomDimension" should be called before "trackPageView" */
_paq.push(['trackPageView']);
_paq.push(['enableLinkTracking']);
(function() {
  var u="//massarn.com/milavu/";
  _paq.push(['setTrackerUrl', u+'matomo.php']);
  _paq.push(['setSiteId', '1']);
  var d=document, g=d.createElement('script'), s=d.getElementsByTagName('script')[0];
  g.async=true; g.src=u+'matomo.js'; s.parentNode.insertBefore(g,s);
})();