In the Scenario Edit Parameters Tab you can customize all the parameters which will be sent to the DITA-OT build file.
All the parameters that can be set to the DITA-OT build files for the chosen type of transformation (eg: XHTML) are listed along with their description. The values for some important parameters are already filled in. You can find more information about each parameter in the DITA OT Documentation
Using the toolbar buttons you can Add, Edit or Remove a parameter.
Depending on the parameter type the parameter value will be a simple text field for simple parameter values, a combo box with some predefined values or will have a file chooser and an editor variables selector to simplify setting a file path as value to a parameter.