Like French Maginot line also Czechoslovak Fortifications were organized into so-called Fortified Sectors. Their names reflected geographical position and in most cases name of near town was used. As sectors were quite large, they were further divided into subsectors.
Sectors were usually ordered by Engineers Headquarters (Czech abbrev. ZSV). At the beginning, casemates were only guarded by small troops, since 1938 special fortress troops had been created.