STOP LINE

SN A notional line of resistance defined by anti tank obstacles, pillboxes and gun emplacements.
CL MILITARY DEFENCE AND FORTIFICATION
BT ANTI INVASION DEFENCE SITE
RT ANTI TANK GUN EMPLACEMENT
ANTI TANK OBSTACLE
BARBED WIRE ENTANGLEMENT
DEFENDED BUILDING
DEFENDED LOCALITY
DEMOLITION CHARGE SITE
FIELDWORK
LYON LIGHT EMPLACEMENT
PETROLEUM WARFARE SITE
PILLBOX
RAILBLOCK
ROADBLOCK
SPIGOT MORTAR EMPLACEMENT