A placement takes a standard geometric construction and places it in geographic space. It defines a transformation from a constructive parameter space to the coordinate space of the coordinate reference system being used. Parameter spaces in formulae in this international standard are given as (u, v) in 2D and (u, v, w) in 3D. Coordinate reference systems positions are given in formulae, in this international standard, by either (x, y) in 2D, or (x, y, z) in 3D.<br/>