An RST consists of zero or more representations. Each included representation is indicated by its representation code, or RepCode. This is the integer value used to look up the representation in the RST, typically based on the RepCode attribute of the shapes in the layer.
The representation consists of a series of zero or more parts. Each part describes a drawing method used when drawing a shape. Normally there is only one part.
Each part has the following information:
Priority: The priority is used to indicate how different vector drawing components should be layered. The higher priority values are drawn over those with lower priorities. This applies between different parts within a given representation, but also applies between different shapes drawn within a given layer, and in some applications is evaluated between all vector layers in a given view.
Graphical Primitive: The drawing primitive to be used for this part. Supported primitives include: Simple-Line, Dash-Line, Spaced-Symbol, Simple-Point, Point-Symbol, Vector-Text, Solid-Polygon, Patterned-Fill, and Transparent-Polygon.
Parameters: Each primitive has a particular set of parameters affecting the display. For instance, the parameters of the Simple-Line primitive are width and colour.