CME Globex will validate iLink 2 orders for tag 11-CIOrdID for uniqueness per SenderComp (Session ID + Firm ID) for all working orders on a single market segment. An order with a duplicate ClOrdID will be rejected with a Session Level Reject (35-MsgType=3) message with tag 58-Text = Duplicate ClOrdID: X not allowed.
A ClOrdID value can be re-used on the same Market Segment only when the prior order is no longer resting, for instance:
- the prior order has been completely filled, or
- the prior order has been cancelled, or
- the prior order has been eliminated.