return array(
    'metadata_class_name' => array(
        // Use as field label
        'label' => __('Metadata class label'),

        // The model of the metadata class's nature
        'nature' => 'Model_Nature',

        // The field configuration used in the CRUD
        'field' => array(
            // By default, field uses the renderer Novius\Metadata\Renderer_Metadata
            'renderer_options' => array(
                // Specify if you want just one metadata for this class
                'single' => false, // True by default

                // If count of nature items is under this number, the renderer will be just a select
                'select_limit' => 50, // 50 by default

                // Translations for different labels in the renderer
                'i18n' => array(
                    'add' => __('Add items'),
                    'choose' => __('Choose an item'),
                    'remove' => __('Remove item'),
                    'edit' => __('Edit item'),
                ),
            ),
        ),
    ),

    'other_metadata_class_name' => array(
        'label' => __('Other Metadata class label'),

        // Nature can be an array with two keys: model and query
        'nature' => array(
            'model' => 'Model_Nature',

            // Additional query on the nature model
            'query' => array(
                'where' => array(
                //...
                ),
            ),
        ),

        'field' => array(
            // A specific renderer for this metadata class.
            // The field's name will be the concatenation of 'metadata_' and the class name
            'renderer' => 'Renderer_Metadata_Class',
            // The renderer_options array will automatically contain a key 'metadata_class'
            // The value of this key is the metadata class config array
            'renderer_options' => array(),
        ),
    ),
);

protected static $_behaviours = array(
    'Novius\Metadata\Behaviour_Hasmetadata' => array(
        // List of metadata classes that you want to exclude for this model
        //'exclude' => array(),

        // List of specific metadata classes. See above metadata classes' configuration.
        //'classes' => array(),
    ),
),