Fotos Gallery Tags Custom Taxonomy

// Add gallery tags taxonomy
add_action( 'init', 'wpex_gallery_tags' );
function wpex_gallery_tags() {
	$tags_labels = array(
		'name' => __( 'Gallery Tags', 'fotos' ),
		'singular_name' => __( 'Gallery Tags', 'fotos' ),
		'search_items' =>  __( 'Search Gallery Tags', 'fotos' ),
		'all_items' => __( 'All Gallery Tags', 'fotos' ),
		'parent_item' => __( 'Parent Gallery Tag', 'fotos' ),
		'parent_item_colon' => __( 'Parent Gallery Tag:', 'fotos' ),
		'edit_item' => __( 'Edit Gallery Tag', 'fotos' ),
		'update_item' => __( 'Update Gallery Tag', 'fotos' ),
		'add_new_item' => __( 'Add New Gallery Tag', 'fotos' ),
		'new_item_name' => __( 'New Gallery Tag Name', 'fotos' ),
		'choose_from_most_used'	=> __( 'Choose from the most used photos albums', 'fotos' )
	);

	register_taxonomy('gallery_tags','gallery',array(
		'public' => true,
		'show_ui' => true,
		'show_in_nav_menus' => true,
		'hierarchical' => true,
		'labels' => $tags_labels,
		'query_var' => true,
		'rewrite' => array( 'slug' => 'gallery-tag' ),
	));
}