The objective of this Standard is to support a consistent approach to identifying engineering processes for the protection of running lines against unauthorized movements of rolling stock. It includes common causes, the possible hazards of unauthorized movements of rolling stock, operational considerations and identifies situations where protection could be required.This Standard provides mandatory and recommended requirements for the differing engineering options to protect running lines against unauthorized movements of rolling stock. The scope of this Standard includes the following: a. Functional requirements. b. Application considerations. c. Network design and operational requirements. The following items are excluded from this Standarda. Onboard systems used for securing rolling stock including hand brakes and chocks.b. Train stops and Automatic Train Protection (ATP) systems.c. Connection of brake pipe to rail when the train is unattended.