Hierarchy classification:

1. top of the aat hierarchies
2. Objects Facet
3. Visual and Verbal Communication (hierarchy name)
4. Information Forms (hierarchy name)
5. information forms (objects)
6. document genres
7. [documents by form]
8. graphic document genres
9. cartographic materials
10. maps (documents)
11. [maps by subject type]

Anotations

Scope note:

Refers to maps of large areas, often an ocean, depicted in a small scale by gnomonic projection. They are laid out to allow calculation of a great-circle route, which is the shortest course between two points on the surface of the sphere of the Earth.