▁own ▁set ▁of ▁operating ▁rules ▁that ▁govern ▁their ▁rail road ▁operations . ▁ ▁Over view ▁The ▁GC OR ▁rules ▁are ▁intended ▁to ▁enh ance ▁rail road ▁safety . ▁The ▁rules ▁cover ▁employee ▁respons ib ilities , ▁signal ing ▁equipment , ▁procedures ▁for ▁safe ▁train ▁movement , ▁dealing ▁with ▁acc idents ▁and ▁other ▁topics ▁that ▁directly ▁and ▁indirect ly ▁affect ▁rail road ▁safety . ▁Some ▁rail ro ads ▁modify ▁the ▁GC OR ▁rules ▁to ▁suit ▁their ▁specific ▁operations . ▁ ▁The ▁GC OR ▁is ▁supp lement ed ▁by ▁System ▁Special ▁Inst ru ctions , ▁Tim et ables , ▁Haz ard ous ▁Material s ▁Inst ru ctions , ▁Air ▁Bra ke ▁and ▁Train ▁Hand ling ▁Inst ru ctions , ▁and ▁General ▁Or ders . ▁ ▁These ▁documents ▁are ▁issued ▁by ▁each ▁individual ▁rail road . ▁ ▁System ▁Special ▁instructions , ▁Tim et ables , ▁and ▁General ▁Order ▁can ▁modify ▁or ▁am end ▁the ▁General ▁Code ▁of ▁Oper ating ▁R ules . ▁ ▁GC OR ▁ 1 . 3 . 2 ▁states ▁that ▁General ▁Or ders ▁replace ▁any ▁rule , ▁special ▁instruction , ▁or ▁reg ulation ▁that ▁conflicts ▁with ▁the ▁general ▁order . ▁ ▁Some ▁rail ro ads ▁will ▁maintain ▁what ▁they ▁call ▁a ▁" l iving ▁rule book ." ▁ ▁As ▁am end ments ▁are ▁released ▁via ▁general ▁order ▁or ▁special ▁instruction , ▁they ▁will ▁update ▁the ▁specific ▁page ▁that ▁was ▁affected . ▁ ▁Most ▁rail ro ads ▁are ▁using ▁the ▁Se vent h ▁Edition , ▁effective ▁April ▁ 1 , ▁ 2 0 1