Here is a list of all documented namespaces with brief descriptions:
[detail level 123]
| ▼Nosgeo | |
| ▼Nproj | |
| Ncommon | Common classes |
| Ncrs | CRS (coordinate reference system = coordinate system with a datum) |
| Ncs | Coordinate systems and their axis |
| Ndatum | Datum (the relationship of a coordinate system to the body) |
| Nio | I/O classes |
| Nmetadata | Common classes from ISO 19115 (Metadata) standard |
| Noperation | Coordinate operations (relationship between any two coordinate reference systems) |
| Nutil | A set of base types from ISO 19103, GeoAPI and other PROJ specific classes |