WordPress at a glance
filter is not described

nav_menu_attr_title filter-hook . WP 3.0.0

Filters a navigation menu item's title attribute.

Usage

add_filter( 'nav_menu_attr_title', 'filter_function_name_5710' );
function filter_function_name_5710( $item_title ){
	// filter...

	return $item_title;
}
$item_title(string)
The menu item title attribute.

Where the hook is called

wp_setup_nav_menu_item()
WP_Customize_Nav_Menu_Item_Setting::value_as_wp_post_nav_menu_item()
wp-includes/nav-menu.php 835
$menu_item->attr_title = ! isset( $menu_item->attr_title ) ? apply_filters( 'nav_menu_attr_title', $menu_item->post_excerpt ) : $menu_item->attr_title;
wp-includes/customize/class-wp-customize-nav-menu-item-setting.php 624
$post->attr_title = apply_filters( 'nav_menu_attr_title', $post->attr_title );
wp-includes/nav-menu.php 870
$menu_item->attr_title = apply_filters( 'nav_menu_attr_title', '' );

Where the hook is used (in WP core)

wp-includes/default-filters.php 135
add_filter( $filter, 'wptexturize' );
wp-includes/default-filters.php 136
add_filter( $filter, 'strip_tags' );