diff --git a/includes/data-stores/abstract-wc-order-data-store-cpt.php b/includes/data-stores/abstract-wc-order-data-store-cpt.php
index 9e0a738da4b..67cbebda782 100644
--- a/includes/data-stores/abstract-wc-order-data-store-cpt.php
+++ b/includes/data-stores/abstract-wc-order-data-store-cpt.php
@@ -220,7 +220,7 @@ abstract class Abstract_WC_Order_Data_Store_CPT extends WC_Data_Store_WP impleme
 	/**
 	 * Helper method that updates all the post meta for an order based on it's settings in the WC_Order class.
 	 *
-	 * @param WC_Order
+	 * @param $order WC_Order
 	 * @since 3.0.0
 	 */
 	protected function update_post_meta( &$order ) {
diff --git a/includes/data-stores/class-wc-customer-download-data-store.php b/includes/data-stores/class-wc-customer-download-data-store.php
index 192b0ad3b01..a4a28f512cc 100644
--- a/includes/data-stores/class-wc-customer-download-data-store.php
+++ b/includes/data-stores/class-wc-customer-download-data-store.php
@@ -13,7 +13,7 @@ if ( ! defined( 'ABSPATH' ) ) {
 class WC_Customer_Download_Data_Store implements WC_Customer_Download_Data_Store_Interface {
 
 	/**
-	 * Create dowload permission for a user.
+	 * Create download permission for a user.
 	 *
 	 * @param WC_Customer_Download $download
 	 */
diff --git a/includes/data-stores/class-wc-data-store-wp.php b/includes/data-stores/class-wc-data-store-wp.php
index 69fc5734be4..1ccc6e92f4a 100644
--- a/includes/data-stores/class-wc-data-store-wp.php
+++ b/includes/data-stores/class-wc-data-store-wp.php
@@ -17,7 +17,7 @@ class WC_Data_Store_WP {
 
 	/**
 	 * Meta type. This should match up with
-	 * the types avaiable at https://codex.wordpress.org/Function_Reference/add_metadata.
+	 * the types available at https://codex.wordpress.org/Function_Reference/add_metadata.
 	 * WP defines 'post', 'user', 'comment', and 'term'.
 	 */
 	protected $meta_type = 'post';
@@ -97,7 +97,7 @@ class WC_Data_Store_WP {
 	 * @since  3.0.0
 	 * @param  WC_Data
 	 * @param  stdClass (containing ->key and ->value)
-	 * @return meta ID
+	 * @return int meta ID
 	 */
 	public function add_meta( &$object, $meta ) {
 		return add_metadata( $this->meta_type, $object->get_id(), $meta->key, $meta->value, false );
diff --git a/includes/data-stores/class-wc-order-data-store-cpt.php b/includes/data-stores/class-wc-order-data-store-cpt.php
index 9ab701ac67d..14e1ffac7c4 100644
--- a/includes/data-stores/class-wc-order-data-store-cpt.php
+++ b/includes/data-stores/class-wc-order-data-store-cpt.php
@@ -240,7 +240,7 @@ class WC_Order_Data_Store_CPT extends Abstract_WC_Order_Data_Store_CPT implement
 
 		parent::update_post_meta( $order );
 
-		// If address changed, store concatinated version to make searches faster.
+		// If address changed, store concatenated version to make searches faster.
 		if ( in_array( 'billing', $updated_props ) || ! metadata_exists( 'post', $id, '_billing_address_index' ) ) {
 			update_post_meta( $id, '_billing_address_index', implode( ' ', $order->get_address( 'billing' ) ) );
 		}
diff --git a/includes/data-stores/class-wc-order-item-coupon-data-store.php b/includes/data-stores/class-wc-order-item-coupon-data-store.php
index c2daeb54a4b..ac2780d20ce 100644
--- a/includes/data-stores/class-wc-order-item-coupon-data-store.php
+++ b/includes/data-stores/class-wc-order-item-coupon-data-store.php
@@ -23,7 +23,7 @@ class WC_Order_Item_Coupon_Data_Store extends Abstract_WC_Order_Item_Type_Data_S
 	 * Read/populate data properties specific to this order item.
 	 *
 	 * @since 3.0.0
-	 * @param WC_Order_Item $item
+	 * @param WC_Order_Item_Coupon $item
 	 */
 	public function read( &$item ) {
 		parent::read( $item );
@@ -40,7 +40,7 @@ class WC_Order_Item_Coupon_Data_Store extends Abstract_WC_Order_Item_Type_Data_S
 	 * Ran after both create and update, so $item->get_id() will be set.
 	 *
 	 * @since 3.0.0
-	 * @param WC_Order_Item $item
+	 * @param WC_Order_Item_Coupon $item
 	 */
 	public function save_item_data( &$item ) {
 		$id          = $item->get_id();
diff --git a/includes/data-stores/class-wc-order-item-data-store.php b/includes/data-stores/class-wc-order-item-data-store.php
index 4ca80262a2c..36bbbaf647a 100644
--- a/includes/data-stores/class-wc-order-item-data-store.php
+++ b/includes/data-stores/class-wc-order-item-data-store.php
@@ -17,7 +17,7 @@ class WC_Order_Item_Data_Store implements WC_Order_Item_Data_Store_Interface {
 	 *
 	 * @since  3.0.0
 	 * @param  int   $order_id
-	 * @param  array $item. order_item_name and order_item_type.
+	 * @param  array $item order_item_name and order_item_type.
 	 * @return int Order Item ID
 	 */
 	public function add_order_item( $order_id, $item ) {
@@ -44,7 +44,7 @@ class WC_Order_Item_Data_Store implements WC_Order_Item_Data_Store_Interface {
 	 *
 	 * @since  3.0.0
 	 * @param  int   $item_id
-	 * @param  array $item. order_item_name or order_item_type.
+	 * @param  array $item order_item_name or order_item_type.
 	 * @return boolean
 	 */
 	public function update_order_item( $item_id, $item ) {
diff --git a/includes/data-stores/class-wc-order-item-fee-data-store.php b/includes/data-stores/class-wc-order-item-fee-data-store.php
index 4826e1fb809..6f748dde876 100644
--- a/includes/data-stores/class-wc-order-item-fee-data-store.php
+++ b/includes/data-stores/class-wc-order-item-fee-data-store.php
@@ -11,6 +11,7 @@ if ( ! defined( 'ABSPATH' ) ) {
  * @author   WooCommerce
  */
 class WC_Order_Item_Fee_Data_Store extends Abstract_WC_Order_Item_Type_Data_Store implements WC_Object_Data_Store_Interface, WC_Order_Item_Type_Data_Store_Interface {
+
 	/**
 	 * Data stored in meta keys.
 	 * @since 3.0.0
@@ -22,7 +23,7 @@ class WC_Order_Item_Fee_Data_Store extends Abstract_WC_Order_Item_Type_Data_Stor
 	 * Read/populate data properties specific to this order item.
 	 *
 	 * @since 3.0.0
-	 * @param WC_Order_Item $item
+	 * @param WC_Order_Item_Fee $item
 	 */
 	public function read( &$item ) {
 		parent::read( $item );
@@ -41,7 +42,7 @@ class WC_Order_Item_Fee_Data_Store extends Abstract_WC_Order_Item_Type_Data_Stor
 	 * Ran after both create and update, so $id will be set.
 	 *
 	 * @since 3.0.0
-	 * @param WC_Order_Item $item
+	 * @param WC_Order_Item_Fee $item
 	 */
 	public function save_item_data( &$item ) {
 		$id          = $item->get_id();
diff --git a/includes/data-stores/class-wc-order-item-product-store.php b/includes/data-stores/class-wc-order-item-product-store.php
index db5a9c9228e..f7f8025b640 100644
--- a/includes/data-stores/class-wc-order-item-product-store.php
+++ b/includes/data-stores/class-wc-order-item-product-store.php
@@ -11,6 +11,7 @@ if ( ! defined( 'ABSPATH' ) ) {
  * @author   WooCommerce
  */
 class WC_Order_Item_Product_Data_Store extends Abstract_WC_Order_Item_Type_Data_Store implements WC_Object_Data_Store_Interface, WC_Order_Item_Type_Data_Store_Interface, WC_Order_Item_Product_Data_Store_Interface {
+
 	/**
 	 * Data stored in meta keys.
 	 * @since 3.0.0
@@ -22,7 +23,7 @@ class WC_Order_Item_Product_Data_Store extends Abstract_WC_Order_Item_Type_Data_
 	 * Read/populate data properties specific to this order item.
 	 *
 	 * @since 3.0.0
-	 * @param WC_Order_Item $item
+	 * @param WC_Order_Item_Product $item
 	 */
 	public function read( &$item ) {
 		parent::read( $item );
@@ -44,7 +45,7 @@ class WC_Order_Item_Product_Data_Store extends Abstract_WC_Order_Item_Type_Data_
 	 * Ran after both create and update, so $id will be set.
 	 *
 	 * @since 3.0.0
-	 * @param WC_Order_Item $item
+	 * @param WC_Order_Item_Product $item
 	 */
 	public function save_item_data( &$item ) {
 		$id          = $item->get_id();
@@ -68,7 +69,7 @@ class WC_Order_Item_Product_Data_Store extends Abstract_WC_Order_Item_Type_Data_
 	 * Get a list of download IDs for a specific item from an order.
 	 *
 	 * @since 3.0.0
-	 * @param WC_Order_Item $item
+	 * @param WC_Order_Item_Product $item
 	 * @param WC_Order $order
 	 * @return array
 	 */
diff --git a/includes/data-stores/class-wc-order-item-shipping-data-store.php b/includes/data-stores/class-wc-order-item-shipping-data-store.php
index 745b2f14d5d..48cd5b8c53d 100644
--- a/includes/data-stores/class-wc-order-item-shipping-data-store.php
+++ b/includes/data-stores/class-wc-order-item-shipping-data-store.php
@@ -11,6 +11,7 @@ if ( ! defined( 'ABSPATH' ) ) {
  * @author   WooCommerce
  */
 class WC_Order_Item_Shipping_Data_Store extends Abstract_WC_Order_Item_Type_Data_Store implements WC_Object_Data_Store_Interface, WC_Order_Item_Type_Data_Store_Interface {
+
 	/**
 	 * Data stored in meta keys.
 	 * @since 3.0.0
@@ -22,7 +23,7 @@ class WC_Order_Item_Shipping_Data_Store extends Abstract_WC_Order_Item_Type_Data
 	 * Read/populate data properties specific to this order item.
 	 *
 	 * @since 3.0.0
-	 * @param WC_Order_Item $item
+	 * @param WC_Order_Item_Shipping $item
 	 */
 	public function read( &$item ) {
 		parent::read( $item );
@@ -40,7 +41,7 @@ class WC_Order_Item_Shipping_Data_Store extends Abstract_WC_Order_Item_Type_Data
 	 * Ran after both create and update, so $id will be set.
 	 *
 	 * @since 3.0.0
-	 * @param WC_Order_Item $item
+	 * @param WC_Order_Item_Shipping $item
 	 */
 	public function save_item_data( &$item ) {
 		$id          = $item->get_id();
diff --git a/includes/data-stores/class-wc-order-item-tax-data-store.php b/includes/data-stores/class-wc-order-item-tax-data-store.php
index 17ef18441e9..5619143ddc5 100644
--- a/includes/data-stores/class-wc-order-item-tax-data-store.php
+++ b/includes/data-stores/class-wc-order-item-tax-data-store.php
@@ -11,6 +11,7 @@ if ( ! defined( 'ABSPATH' ) ) {
  * @author   WooCommerce
  */
 class WC_Order_Item_Tax_Data_Store extends Abstract_WC_Order_Item_Type_Data_Store implements WC_Object_Data_Store_Interface, WC_Order_Item_Type_Data_Store_Interface {
+
 	/**
 	 * Data stored in meta keys.
 	 * @since 3.0.0
@@ -22,7 +23,7 @@ class WC_Order_Item_Tax_Data_Store extends Abstract_WC_Order_Item_Type_Data_Stor
 	 * Read/populate data properties specific to this order item.
 	 *
 	 * @since 3.0.0
-	 * @param WC_Order_Item $item
+	 * @param WC_Order_Item_Tax $item
 	 */
 	public function read( &$item ) {
 		parent::read( $item );
@@ -42,7 +43,7 @@ class WC_Order_Item_Tax_Data_Store extends Abstract_WC_Order_Item_Type_Data_Stor
 	 * Ran after both create and update, so $id will be set.
 	 *
 	 * @since 3.0.0
-	 * @param WC_Order_Item $item
+	 * @param WC_Order_Item_Tax $item
 	 */
 	public function save_item_data( &$item ) {
 		$id          = $item->get_id();
diff --git a/includes/data-stores/class-wc-order-refund-data-store-cpt.php b/includes/data-stores/class-wc-order-refund-data-store-cpt.php
index 2c44bb15fed..2a299064124 100644
--- a/includes/data-stores/class-wc-order-refund-data-store-cpt.php
+++ b/includes/data-stores/class-wc-order-refund-data-store-cpt.php
@@ -35,7 +35,7 @@ class WC_Order_Refund_Data_Store_CPT extends Abstract_WC_Order_Data_Store_CPT im
 
 	/**
 	 * Delete a refund - no trash is supported.
-	 * @param WC_Order
+	 * @param WC_Order $order
 	 * @param array $args Array of args to pass to the delete method.
 	 */
 	public function delete( &$order, $args = array() ) {
@@ -49,7 +49,7 @@ class WC_Order_Refund_Data_Store_CPT extends Abstract_WC_Order_Data_Store_CPT im
 	/**
 	 * Read refund data. Can be overridden by child classes to load other props.
 	 *
-	 * @param WC_Order
+	 * @param WC_Order $refund
 	 * @param object $post_object
 	 * @since 3.0.0
 	 */
@@ -67,7 +67,7 @@ class WC_Order_Refund_Data_Store_CPT extends Abstract_WC_Order_Data_Store_CPT im
 	 * Helper method that updates all the post meta for an order based on it's settings in the WC_Order class.
 	 *
 	 * @param WC_Order
-	 * @param bool $force Force all props to be written even if not changed. This is used during creation.
+	 * @param WC_Order $refund
 	 * @since 3.0.0
 	 */
 	protected function update_post_meta( &$refund ) {
diff --git a/includes/interfaces/class-wc-order-item-data-store-interface.php b/includes/interfaces/class-wc-order-item-data-store-interface.php
index 5e61798fd91..751bb5d1125 100644
--- a/includes/interfaces/class-wc-order-item-data-store-interface.php
+++ b/includes/interfaces/class-wc-order-item-data-store-interface.php
@@ -13,10 +13,11 @@ if ( ! defined( 'ABSPATH' ) ) {
  * @author   WooCommerce
  */
 interface WC_Order_Item_Data_Store_Interface {
+
 	/**
 	 * Add an order item to an order.
 	 * @param  int   $order_id
-	 * @param  array $item. order_item_name and order_item_type.
+	 * @param  array $item order_item_name and order_item_type.
 	 * @return int   Order Item ID
 	 */
 	public function add_order_item( $order_id, $item );
@@ -24,7 +25,7 @@ interface WC_Order_Item_Data_Store_Interface {
 	/**
 	 * Update an order item.
 	 * @param  int   $item_id
-	 * @param  array $item. order_item_name or order_item_type.
+	 * @param  array $item order_item_name or order_item_type.
 	 * @return boolean
 	 */
 	public function update_order_item( $item_id, $item );
diff --git a/includes/wc-order-item-functions.php b/includes/wc-order-item-functions.php
index 368008ed1bb..a325c311d58 100644
--- a/includes/wc-order-item-functions.php
+++ b/includes/wc-order-item-functions.php
@@ -20,9 +20,7 @@ if ( ! defined( 'ABSPATH' ) ) {
  * @return mixed
  */
 function wc_add_order_item( $order_id, $item ) {
-	$order_id = absint( $order_id );
-
-	if ( ! $order_id )
+	if ( ! $order_id = absint( $order_id ) )
 		return false;
 
 	$defaults = array(
@@ -69,13 +67,13 @@ function wc_update_order_item( $item_id, $args ) {
  * @return bool
  */
 function wc_delete_order_item( $item_id ) {
-	$item_id    = absint( $item_id );
-	$data_store = WC_Data_Store::load( 'order-item' );
 
-	if ( ! $item_id ) {
+	if ( ! $item_id = absint( $item_id ) ) {
 		return false;
 	}
 
+	$data_store = WC_Data_Store::load( 'order-item' );
+
 	do_action( 'woocommerce_before_delete_order_item', $item_id );
 
 	$data_store->delete_order_item( $item_id );