CD103 ABAP Development Guidelines
ABAP is a vibrant, evolving language which is almost 30 years old. New developments in ABAP are introduced either through additions to the existing feature set or replacement (and thereby making superfluous or obsolete) of current features while SAP's practice of maintaining strict downward compatibility prevents the total extinction of obsolete features from the language. This issue of superfluity and obsolescence can be troublesome. The ABAP programming guidelines help you to find your way through that jungle of possibilities and to create programs that are correct, robust, readable, maintainable, and up-to-date.