In a rigiedit operation, you may be required to specify a particular arc type (through the Arc Type palette) or a set of arc types (through the Arc Set popup menu in the Settings dialog).
Most arc types are domain-specific; following is a description of the domain-independent arc types that arise when producing a subsystem containment hierarchy.
A level arc spans two adjacent levels in a subsystem hierarchy.
A composite arc represents a bundle of one or more arcs of different types.
Subsystem nodes generally have composite arcs incident to them.
The level and composite arc types are automatically added if not present in the loaded domain model.
Technical: Multiple types of level and composite arcs are supported
through RCL commands.
Essentially, any arc type can become the current level or
composite arc type.
By default, the current level and composite arc types are
the ones named, respectively, level and
composite.