desitop

Thanks much appreciated. I fixed it with this code

function alt_message() {
  return "AVAILABLE ONLY FOR PRE-ORDER. Please note that this item may take 2-3 weeks to ship.";
}

function backorder_text($availability) {
$altmessage = alt_message();
foreach($availability as $i) {
$availability = str_replace('Available on backorder', $altmessage, $availability);
}
return $availability;
} 
add_filter('woocommerce_get_availability', 'backorder_text');

function woocommerce_custom_cart_item_name( $_product_title, $cart_item, $cart_item_key ) {
$altmessage = alt_message();
  if ( $cart_item['data']->backorders_require_notification() && $cart_item['data']->is_on_backorder( $cart_item['quantity'] ) ) {
$_product_title .=  __( ' - '. $altmessage, 'woocommerce' ) ;
}
return $_product_title;
}
add_filter( 'woocommerce_cart_item_name', 'woocommerce_custom_cart_item_name', 10, 3);