Name	Notation	Description	Types	Status
Area	area	a two-dimensional feature, either a plane, or some other surf...	Concept	stable
inapplicable	inapplicable	observing geometry inapplicable	Concept	stable
Line	line	a one-dimensional feature, either a straight line, or a curve...	Concept	stable
Point	point	a zero-dimensional feature	Concept	stable
Total column	totalColumn	the integral of the vertical distribution of a feature	Concept	stable
unknown	unknown	observing geometry unknown	Concept	stable
Vertical profile	verticalProfile	synonymous to vertical distribution of a feature	Concept	stable
Volume	volume	a three-dimensional feature	Concept	stable