CL, as provided by IBM, only supports message subfiles. The <a href=”http://www.powercl.com/”>PowerCL: CL for Files</a> product allows full support for subfiles. The display file containing the subfile record formats can be declared with either the <a href=”http://www.powercl.com/clf/clfcommands/dclfclf”>Declared File using CLF (DCLFCLF)</a> command or the <a href=”http://www.powercl.com/clf/clfcommands/file”>File Description Specification (FILE)</a> command.
(one of the PowerCL: CLF developers)
You can declare a Physical, Logical or Display file in CL/400 using the DCLF statement. You can read a Physical or Logical using the RCVF statement. You can write a Display file record using the SNDF command or read one using the RCVF command, you can write and read a Display file record using the SNDRCVF command.
CL/400 (to my knowledge) does not support subfile display formats. For subfile processing you will need to use a HLL such as RPG or COBOL.