In my previous post I stated that IBM had removed the RPG400 user's guide and reference from the KnowledgeCenter.
Having performed a good deal of searching of the internet I have been able to find copies of both of these manuals in a dark corner of the IBM website. The manuals are from 2000. That may seem a long time ago for a "current" manual, but RPG3 has not been enhanced since RPG4 was introduced 23 years ago.
I have uploaded both of these PDF files to my Dropbox account, and you can reach them by using the following links:
Having given you these links I trust you will only refer to these manuals to remind yourself of some of the anachronisms of old RPG, rather than use to develop new code.