Policy For Stacking Shipping promotions

If you have a client that requires multiple shipping promotions to be applied on an order.
By default there can only be 1 shipping promotion applied on any order.

1). update px_policy set status = 1 where name in ('Shipping: Any order item can only participate in one promotion') and store_id = STORE_ID
2). Get the xmlparam data for this policy: select xmlparam from px_policy where name in ('Shipping: Any order item can only participate in one promotion') and store_id = STORE_ID
3). Update the xmlparam
Before:
<PromotionPolicy impl="com.ibm.commerce.marketing.promotion.policy
.EachItemCanParticipateInPromotionOncePolicy"
&.......;/StoreKey></PromotionPolicyKey><Status>Active</Status></PromotionPolicy>
After:
<PromotionPolicy impl="com.ibm.commerce.marketing.promotion.policy.
EachItemCanParticipateInPromotionOncePolicy"&
.........;</StoreKey></PromotionPolicyKey><Status>Inactive</Status></PromotionPolicy>

4). restart the server