The Open API provides a way to configure the elements' Specification windows. With your own configurator you can create new nodes or remove already existing nodes. Nodes are items of the tree visible on the left side in every Specification window.
The com.nomagic.magicdraw.ui.dialogs.specifications.SpecificationDialogManager class should be used for registering a specification dialog configurator com.nomagic.magicdraw.ui.dialogs.specifications.configurator.ISpecificationNodeConfigurator.
More information is available in javadoc.
You can find the code examples in <programinstallation directory>/openapi/examples/elementspecification