Rules for modifying DD statements in concatenated data sets

  • To override the first DD statement in a concatenation, code only one overriding DD statement.
  • To override any following DD statements in the concatenation, code an overriding DD statement for each concatenated DD statement.
  • The overriding DD statements must be in the same order as the concatenated DD statements.
  • Code a ddname on only the first overriding DD statement. Leave the ddname field blank on the following statements.
  • To leave a concatenated statement unchanged, code its corresponding overriding DD statement with a blank operand (or parameter) field.