Many different requirements for application software documentation are presently being specified for software used in rail equipment and systems and for related applications. This has led to a lack of standardization in the information provided on equipment and systems incorporating software. This standard, when used by the authority having jurisdiction, car builders and system/subsystem suppliers is intended to specify documents which improve the understanding of software functionality, facilitate software corrections and upgrades, improve on-time delivery, assist the development of quality software, and lower software acquisition and maintenance costs.