woocommerce_order_get_tax_totals filter-hook . WC 1.0

Usage

add_filter( 'woocommerce_order_get_tax_totals', 'filter_function_name_6275', 10, 2 );
function filter_function_name_6275( $tax_totals, $that ){
	// filter...

	return $tax_totals;
}

$tax_totals

-

$that

-

Where the hook is called

return apply_filters( 'woocommerce_order_get_tax_totals', $tax_totals, $this );

Where in WP core the hook is used WooCommerce