autoship_update_scheduled_order_shipping_address_invalid_fields (action)

(src/scheduled-orders.php) Allows customization to be added to the invalid notices returned when updating the shipping address on a Scheduled Order. It takes the $invalids (notices) and the (form) $fields as parameters.

Code 

// Allow others to add on additional invalid notices
do_action( 'autoship_update_scheduled_order_shipping_address_invalid_fields', $invalids, $fields );

Found in the Functions