Definitions and Functions of Signals - Forward Line Signals. Backward Line Signals. Forward Register Signals. Backward Register Signals - Specifications of Signalling Systems R1 and R2 (Study Group XI) 4 pp
Some of the Group II forward signals (see Recommendation 4.441, 8 4.2.3.2) have been allocated for national use. When the outgoing international R2 register receives them, it must react as specified in Recommendation
4.480.