In addition to the out-of-the-box business function plugins, it is possible to develop configurable plugins via the Extension API which then display in the Edit Operation dropdown. The following screenshot shows the UI of a user-defined plugin named 'Allergen Warning Producer', created with the Extension API:
As displayed in this example, with Java business plugins, it is possible to assign a fixed value for some input parameters while leaving others to be provided by the caller. This means that the same plugin can be configured differently in different business functions, thereby exposing different caller 'interfaces.'
For more information on creating business function plugins with the API, refer to the STEP Extension API Guide available via the Technical Documentation accessible at [system]/sdk or from the Resources section of the system's Start Page.