They are merely marked as being character, integer, etc. Every other feature is derived from it. This describes the precise kind of class it is and corresponds to the items in the National Topographic Data Dictionary. Classes have been derived from it to correspond to each subject area in the data model to give an idea of the sort of information that will be stored. Where extra attributes are needed, these are listed.
Features have the possibility of being named.
The way a name is drawn on the map is indicated by the annotation. You can have annotation for a name in the nomenclature list, or for another name that doesn't appear there. The time-varying nature of the data is stored by recording many versions with different retired dates and created dates. Finally, there has been a lot of demand to store detailed information about roads, so routes like bus routes can be depicted. This has been implemented by defining routes as a hierarchy, and connecting routes to a series of segments.