RPG 4
From MidrangeWiki
Note that RPG 4 can do just about anything that could be done by earlier versions of RPG such as RPG/400 and an enormous volume of additional capabilities.
References
RPG IV with free format op codes
Built In Functions
Program To System Fields
Data Structure Information
Program Status Data Structure
Workstation Data Structure
Code Samples
Locate field value field name
SQLSTATE Constants
