This how-to guide offers a concise and thorough introduction to the increased productivity, better readability, and easier program maintenance that comes with the free-format style of programming in RPG IV. Although free-format information is available in IBM manuals, it is not separated from everything else, requiring hours of tedious research to track down the information needed. This book provides everything you need to know to write RPG IV in the free-format style. Author Jim Martin not only teaches rules and syntax, but also explains how this modern style of coding has the potential to improve overall programmer productivity—from initial development through maintenance. He methodically covers the many style issues, such as named indicators and built-in functions, and addresses topics including input and output, program flow, data manipulation, math operations, prototyping, and APIs. This third edition is updated to V7.1 of the IBM i operating system on IBM Power machines. An added chapter explains the new free-format H, F, D, and P specifications introduced by IBM in Technology Refresh 7, and programming examples throughout the book are updated to reflect the new specifications.