Class II subset - engineering drawings. Exchange emphasis is on completeness, visual equivalency for human interpretation, and functionality of the received drawing. Information requirements and data functionality. Currently, engineering drawings form the mainstay of product definition and form the accepted medium for viewing computer generated data. Geometry and text annotation form the majority of data items.
Extensive use is made of dimensions, sectioned areas, text notes, and feature control symbols.
Non-geometric information in the form of color, line weight, line font, and level is needed as well. Finally, relationships among the data help to structure the large quantities of data. Simple geometry in the form of points, lines, circular arcs, conic arcs, and spline curves. Non-geometric attributes of color, line weight, and line font. Data relationships, including the concept of subfigures.