The Authority for the assisting Rail Traffic to enter the Section from the rear is:
on double line Automatic Signalling Sections, the normal Proceed Aspect on the
Signal, where available, or verbal permission from the Train Controller when the
Proceed Aspect is unavailable;
on single line Automatic Signalling Sections, verbal permission from the Train
Controller;
o a Relief Rail Traffic Authority (RRTA); and
o if returning to the rear, the Half Pilot Key from that Location.