Boundary-Line data is output in a layered structure. This is a simplified file structure whereby the boundaries are supplied as individual files; for example, the county file contains only counties.
Ceremonial and Historical counties are provided in separate directories called Supplementary_Ceremonial and Supplementary_Historical, respectively. Historic European Regions are provided in a separate Supplementary_Historic_European_Region directory and Country outlines are provided in a separate Supplementary_Country directory.
