Final answer:
Crews use a Track Warrant for authority to occupy a section of the track and a Form D for managing track occupancy and ensuring safe distances between trains.
Step-by-step explanation:
The two documents crews use to identify switching tasks and what each is used for are Track Warrant and Form D. A Track Warrant is used to give a train the authority to occupy a certain section of the track, this means that it has permission from the dispatcher to use that particular piece of the line. The Form D, on the other hand, is used for track occupancy, which helps manage and ensure safe spacing between trains that are operating on the track.