gistfile1.aw

add_filter( 'wp_nav_menu_args', 'tgm_custom_nav_menu_args' );
function tgm_custom_nav_menu_args( $args ) {

	$args['unique'] = $args['theme_location'];
	
	return $args;

}

add_filter( 'wp_nav_menu_objects', 'tgm_filter_nav_menu', 10, 2 );
function tgm_filter_nav_menu( $objects, $args ) {

	foreach ( $objects as $object ) {
		if ( isset( $args->unique ) )
			$object->url = add_query_arg( array( 'unique' => $args->unique, 'ref' => $args->theme_location ), $object->url );
		else 
			$object->url = add_query_arg( 'ref', $args->theme_location, $object->url );
	}
	
	return $objects;

}