GCOR 6.28 and sub categories

6.28 Movement on Other than Main Track

Except when moving on a main track or on a track where a block system is in effect, trains or engines must move at a speed that allows them to stop within half the range of vision short of:
Train
Engine
Railroad car
Men or equipment fouling the track
Stop signal or Derail or switch lined improperly

6.28.1 Sidings of Assigned Direction

Do not use sidings of an assigned direction in the opposite direction unless authorized by the train dispatcher.

6.28.2 Stopping Clear in Siding

When possible, a train entering a siding must not stop until the entire train is clear of the main track.

6.28.3 Cars or Equipment Left on Siding

Avoid leaving cars or equipment on sidings unless authorized by the train dispatcher, except in an emergency. In this case, notify the train dispatcher immediately.