Order Cancel Request StandardHeader Standard Header Y MsgType = F 41 OrigClOrdID OrigClOrdID Y Unique ID of original order as assigned by institution 37 OrderID OrderID N Broker ID of original order 11 ClOrdID ClOrdID Y Unique ID of cancel request as assigned by the institution. 66 ListID ListID N Required for List Orders 125 CxlType CxlType Y 109 ClientID ClientID N Used for firm identification in third-party transactions. 76 ExecBroker ExecBroker N Used for firm identification in third-party transactions. 55 Symbol Symbol Y 65 SymbolSfx SymbolSfx N 48 SecurityID SecurityID N 22 IDSource IDSource N 106 Issuer Issuer N 107 SecurityDesc SecurityDesc N 54 Side Side Y 38 OrderQty OrderQty Y Original OrderQty for CxlType=F or new OrderQty for CxlType=P. 58 Text Text N StandardTrailer Standard Trailer Y