This is a reusable definition. Requiredness is relative to this structure; its use and conditions in a message remain on that message's page. Version links browse the other dictionary, not an assumed equivalent component.
Quantity or volume represented by the Market Data Entry. In the context of the Market Data Request this allows the Initiator to indicate the quantity of the market data request. Specific to FX this field indicates the ceiling amount the customer is seeking prices for.