title: Why does jQuery.ajax() add a parameter to the url?
body: <p>I have a data fetching method that uses <code>jQuery.ajax()</code> to fetch xml files. </p>
  
  <pre><code>/*    */data: function() {                                                                                                                                          
                                                                                                                                                                  /* debug */try {
          var url = arguments[0] ;                                                                                                                                
          var type = arguments[1] ;                                                                                                                               
          var scope = arguments[2] ;                                                                                                                              
          var callback = arguments[3] ;                                                                                                                           
  
          var self = this ;                                                                                                                                       
              if(this.cache[url]) {                                                                                                                               
                  callback(this.cache[url]) ;                                                                                                                     
              } else if(!this.cache[url]) {                                                                                                                       
  
                  $.ajax({                                                                                                                                        
                      type: "GET" ,                                                                                                                               
                      url: url ,                                                                                                                                  
                      dataType: type ,                                                                                                                            
                      cache: false ,                                                                                                                              
                      success: function(data) {                                                                                                                   
  
                              if(type == "text/xml") {                                                                                                                                                                                                                                                                                
                                  var myJson = AUX.json ;                                                                                                         
                                  var jsonString = myJson.build(data,scope,null) ;                                                                                
                                  var jsonObject = $.parseJSON(jsonString) ;                                                                                      
                                  self.cache[url] = jsonObject ;                                                                                                  
                                  callback(url) ;                                                                                                                 
  
                              } else if(type == "json") {                                                                                                         
  
                                  self.cache[url] = data ;                                                                                                        
                                  callback(url) ;                                                                                                                 
  
                              }                                                                                                                                   
  
                      } ,                                                                                                                                         
                      error: function() {                                                                                                                         
                          throw "Ajax call failed." ;                                                                                                             
                      }                                                                                                                                           
                  }) ;                                                                                                                                            
  
              }                                                                                                                                                   
                                                                                                                                                                  /* debug */} catch(e) {
                                                                                                                                                                  /* debug */     alert("- caller: signTutor.data\n- " + e) ;
                                                                                                                                                                  /* debug */}
      } ,                                                                                                                                                         
  </code></pre>
  
  <p>My problem is: jQuery somehow adds a parameter (<code>?_=1272708280072</code>) to the url if there are escaped (hexadecimal notation) or unescaped utf-8 characters outside of the ASCII range -- i believe -- in the file name. It all works well if the file name does not contain characters in that range.</p>
  
  <p>Type is set to <code>xml</code> so there should not be a confusion of types. Headers of the xml files are also set adequately.</p>
  
  <p>I can see from the console that jQuery throws an error, but I'm not sure as to where the problem really is.</p>
  
  <p>Probably a problem with file name formatting, but I did not find any resources on the web as to AJAX file name specifications. Any ideas?</p>
  
  <p>Thanks for you help!</p>