The rules cover employee responsibilities, signaling equipment, procedures for safe train movement, dealing with accidents and other topics that directly and indirectly affect railroad safety.
Some railroads modify the GCOR rules to suit their specific operations.
As amendments are released via general order or special instruction, they will update the specific page that was affected.
[1] An example of this is the Union Pacific, which maintains a copy of the GCOR with page-by-page amendments.
[3] The current version of the GCOR is the Eighth Edition, effective April 1, 2020.