Data set
               options specify actions that apply only to a SAS data set. Using data
               set options enables you to perform these actions:  
               
               
               
                  
                  
                     
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                     - 
                        
                        
                           
                           select the first or last n observations
                              for processing
                              
                           
                           
                         
                        
                      
                     
                     - 
                        
                        
                           
                           drop variables from processing
                              or from the output data set
                              
                           
                           
                         
                        
                      
                     
                     - 
                        
                        
                           
                           specify a password for a data set