woocommerce_validate_postcode │ filter-hook │ WC 1.0

Usage

add_filter( 'woocommerce_validate_postcode', 'wp_kama_woocommerce_validate_postcode_filter', 10, 3 );

/**
 * Function for `woocommerce_validate_postcode` filter-hook.
 * 
 * @param  $valid    
 * @param  $postcode 
 * @param  $country  
 *
 * @return 
 */
function wp_kama_woocommerce_validate_postcode_filter( $valid, $postcode, $country ){

	// filter...
	return $valid;
}

$valid

-

$postcode

-

$country

-

Where the hook is called

return apply_filters( 'woocommerce_validate_postcode', $valid, $postcode, $country );

Where the hook is used in WooCommerce