The DEFINE statement and its substatement define the table element table_footer. The FOOTER argument declares table_footer as a footer. The TEXT statement specifies the text of the footer. When ODS binds the data component to the table definition (in the DATA step that follows), it will resolve the value of the macro variable SYSDATE9.
   define footer table_footer;
      text 'Prepared on ' sysdate9;
   end;