woocommerce_order_item_display_meta_key │ filter-hook │ WC 1.0

Usage

add_filter( 'woocommerce_order_item_display_meta_key', 'wp_kama_woocommerce_order_item_display_meta_key_filter', 10, 3 );

/**
 * Function for `woocommerce_order_item_display_meta_key` filter-hook.
 * 
 * @param  $display_key 
 * @param  $meta        
 * @param  $that        
 *
 * @return 
 */
function wp_kama_woocommerce_order_item_display_meta_key_filter( $display_key, $meta, $that ){

	// filter...
	return $display_key;
}

$display_key

-

$meta

-

$that

-

Where the hook is called

'display_key'   => apply_filters( 'woocommerce_order_item_display_meta_key', $display_key, $meta, $this ),

Where the hook is used in WooCommerce