You can specify axis labels by assigning labels to particular variables in the input data set, as summarized in the following table:
| 
                   Axis  | 
                      
                    
                      
               
                   Input Data Set  | 
                      
                    
                      
               
                   Variable  | 
                      
                    
                    
            
|---|---|---|
| 
                   Horizontal  | 
                    
                      
                      
               
                   all  | 
                    
                      
                      
               
                   subgroup-variable  | 
                    
                    
            
| 
                   Vertical  | 
                    
                      
                      
               
                   DATA=  | 
                    
                      
                      
               
                   process  | 
                    
                    
            
| 
                   Vertical  | 
                    
                      
                      
               
                   HISTORY=  | 
                    
                      
                      
               
                   subgroup number nonconforming variable  | 
                    
                    
            
| 
                   Vertical  | 
                    
                      
                      
               
                   TABLE=  | 
                    
                      
                      
               
                      | 
                    
                    
            
For an example, see Labeling Axes.