A literal is any of: 
               
            
 
            
             
               	 
               - A character-string whose value is implied by the ordered set of characters of which it is composed 
                  	 
               
  
               	 
               - A reserved word which references a figurative constant 
                  	 
               
  
               	 
               
 A user-defined word which references a constant value 
                  	 
                 
               
            
 
            
            Every literal belongs to one of these types; nonnumeric, numeric, national, or UTF-8.