woocommerce_email_heading_customer_refunded_order filter-hook . WC 1.0

Usage

add_filter( 'woocommerce_email_heading_customer_refunded_order', 'filter_function_name_8505', 10, 3 );
function filter_function_name_8505( $format_string, $object, $that ){
	// filter...

	return $format_string;
}

$format_string

-

$object

-

$that

-

Where the hook is called

return apply_filters( 'woocommerce_email_heading_customer_refunded_order', $this->format_string( $heading ), $this->object, $this );

Where in WP core the hook is used WooCommerce