a blog tool which allows the author of a blog post to link back to and inform a second blog site that its material has been quoted
                                                            
                                                     
                        
                                                
                        
                        
                            a HTTP POST request of type application/x-www-form-urlencoded (the response is XML, and XML handles encoding problems very well)
                                                            
                                                     
                        
                                                
                        
                        
                            a method for establishing a link between two sites