2.3.10.

scd    Maximum differential travel that the compensator is capable to accommodate, due to its geometric and constructive properties, when only one brake operates in the forward direction and the other in reverse direction, while allowing equal tension in both cables/rods.
(See Figure 5A of appendix 1)

a5c0
2.3.12. scd: Differential travel at compensator when only one brake operates in the forward direction and the other in the reverse direction[1] a0c0