Delivery orders are the industry standard way, and the only way, of transferring cask ownership at the warehouse level. If you do not receive one then you do not have full autonomy over your investment.
Think of delivery orders as the equivalent of receiving the v5 document when you buy a car.
Remember: A certificate of title, acquisition, or ownership is not a substitute for a delivery order.
The above video will explain all that you need to know. Alternatively, you can read our comprehensive blog on delivery orders.