Free Tutorial on AS400 Subfiles in ILE RPG (RPG-IV)
After learning the basic concepts of ILE RPG IV an RPG programmer's next stop is Subfiles. AS/400 Subfiles should always be learnt after one has acquired basic skills of RPG IV. One should be able to understand the basic RPG IV concepts like Processing display files, Record Formats, Physical Files, Logical Files, How to interact with database files and finally how to process an interactive display file.

If you do not know any of the above topics, you should first learn the Basic concepts of AS400 ILE RPG.