Field CashMargin (544) - FIX Protocol FIX.5.0SP2
Identifies whether an order is a margin order or a non-margin order. This is primarily used when sending orders to Japanese exchanges to indicate sell margin or buy to cover. The same tag could be assigned also by buy-side to indicate the intent to sell or buy margin and the sell-side to accept or reject (base on some validation criteria) the margin request.
Added in protocol FIX.4.3