Representation Rules control how Design elements are drawn. Each Rule can specify a given type or types of element, or named elements. Representation Rules refer to Styles. The attributes of a Style define a series of drawing styles and colours, for example, for frontface, backface and centreline, and whether items such as p-lines and obstruction volumes are shown. Refer to Colours and Styles for further information.

Representation Rules also control which design elements are to be replaced by symbols when a 2D View is created. Refer to 2D Symbolic Representation for further information.

Representation Rules can be created in a Library and be referred to from a VIEW, or they can be owned directly by a VIEW, in which case they are known as local rules. Local Rules override Library Rules. Refer to Local Rules for further information about the order in which Rules are applied.

Representation Rules (RRUL) are stored in Representation Rulesets (RRST), which in turn are owned by Representation Libraries (RPLB).

This Section also describes Hatching Rules, which are used for automatic hatching of faces of Design elements. Refer to Automatic Hatching for further information.

Refer to Change Highlighting for information on how changes to design elements can be shown.