I am currently building out the FIX Allocation J message. I am seeking more details for the Allocation repeating group field ClOrdID (Tag 11). I am not 100% certain what the field should represent. Any info would be helpful.
CloOrdID(11) or OrderID(37) allow you to reference entire orders that were traded one or more times and the resulting executions/trades are subject to the AllocationInstruction(35=J) you are sending.
Apologies for the late reply. This means to me that the fields remains unchanged as an order may be cancel/replaced. This will allow the history of an order to be easily identified. Is this correct?
OrderID(37) typically does not change during the lifetime of an order. ClOrdID(11) must change when you do message chaining in order to support order history from the perspective of the submitter. The ExecutionReport with a (partial) fill will contain the ClOrdID(11) at the time of the fill and you can reference that in your allocation message. If you allocate partial fills of an order while it is still trading (and being modified), the ClOrdID value will change. It depends on your allocation workflow to determine which cases may apply.