|  | 
                
                    
                         
                             |  Constants | 
                          
                         
                             |  uni-dir   | 
                             1 | 
                             Uni-directional | 
                             
                                  Unidirectional 
                              | 
                          
                         
                             |  bi-dir   | 
                             2 | 
                             Bi-directional | 
                             
                                  Unidirectional 
                              | 
                          
                         
                             |  uni-dir-ignore   | 
                             3 | 
                             Uni-directional-Ignore | 
                             
                                  Unidirectional-Ignore - used with the dummy Rule Mo,
                                                      which accompanies the bi-dir Rule Mo 
                              | 
                          
                         
                             | DEFAULT  | 
                             uni-dir(1) | 
                             Uni-directional | 
                             
                                  Unidirectional 
                              | 
                          
                    
                 
                 |