GDL has directives that define and work with configurations.
GDL contains the following configuration directives:
*Feature defines a configuration parameter that relates to features.
*Option defines a set of allowed states that can be assigned to each configuration parameter. These allowed states are known as options.
*Switch, *Case, and Default establish a dependency on a specified configuration parameter.
*DefaultOption constructs a default configuration.
*Constraints and *InvalidCombinations specify invalid configurations. If these directives are encountered, the GDL parser will attempt to modify them to create a valid (or unconstrained) configuration.
For more information about configuration directives, see GDL Configurations.