WordPress at a glance
filter is not described

woocommerce_shipping_rate_label filter-hook . WC 1.0

Set rate label.

Usage

add_filter( 'woocommerce_shipping_rate_label', 'filter_function_name_1483', 10, 2 );
function filter_function_name_1483( $data_label, $that ){
	// filter...

	return $data_label;
}
$data_label
-
$that
-

Where the hook is called

WC_Shipping_Rate::get_label()
woocommerce_shipping_rate_label
woocommerce/includes/class-wc-shipping-rate.php 200
return apply_filters( 'woocommerce_shipping_rate_label', $this->data['label'], $this );

Where in WP core the hook is used WooCommerce

woocommerce/includes/wc-core-functions.php 43
add_filter( 'woocommerce_shipping_rate_label', 'sanitize_text_field' ); // Shipping rate label.