Object containing custom attributes for competence. Custom attributes can be almost anything, but they are defined specifically for each installation of Snapper Grape, and not part of the standard Snapper Grape data model. They are presented on the form (whether or not they are presented as simple value or object with "value" and "display_value", depends on the specific implementation):

    custom_attribute_name: custom_attribute_value,
    other_custom_attribute_name: {
        value: other_custom_attribute_value
        display_value: other_custom_attribute_display_value