Confirmation/FIX.4.4-5.0SP1

Message Content of Confirmation (MsgType=AK)

TagText	FieldName or ComponentName	Required	Description
	StandardHeader	x	MsgType = AK
664	ConfirmID	x	Unique ID for this message
772	ConfirmRefID		Mandatory if ConfirmTransType is Replace or Cancel
859	ConfirmReqID		Only used when this message is used to respond to a confirmation request (to which this ID refers)
666	ConfirmTransType	x	New, Cancel or Replace
773	ConfirmType	x	Denotes whether this message represents a confirmation or a trade status message
797	CopyMsgIndicator		Denotes whether or not this message represents copy confirmation (or status message) Absence of this field indicates message is not a drop copy.
650	LegalConfirm		Denotes whether this message represents the legally binding confirmation Absence of this field indicates message is not a legal confirm.
665	ConfirmStatus	x
	Parties		Insert here the set of "Parties" (firm identification) fields defined in "Common Components of Application Messages" Required for fixed income Also to be used in associated with ProcessCode for broker of credit (e.g. for directed brokerage trades) Also to be used to specify party-specific regulatory details (e.g. full legal name of contracting legal entity, registered address, regulatory status, any registration details)
	OrdAllocGrp		Indicates number of orders to be combined for allocation. If order(s) were manually delivered set to 1 (one).Required when AllocNoOrdersType = 1
70	AllocID		Used to refer to an earlier Allocation Instruction.
793	SecondaryAllocID		Used to refer to an earlier Allocation Instruction via its secondary identifier
467	IndividualAllocID		Used to refer to an allocation account within an earlier Allocation Instruction.
60	TransactTime	x	Represents the time this message was generated
75	TradeDate	x
	TrdRegTimestamps		Time of last execution being confirmed by this message
	Instrument	x	Insert here the set of "Instrument" (symbology) fields defined in "Common Components of Application Messages"
	InstrumentExtension		Insert here the set of "InstrumentExtension" fields defined in "Common Components of Application Messages"
	FinancingDetails		Insert here the set of "FinancingDetails" fields defined in "Common Components of Application Messages"
	UndInstrmtGrp	x	Indicates number of repeating entries. ** Nested Repeating Group follows **
	InstrmtLegGrp	x	Indicates number of repeating entries. ** Nested Repeating Group follows **
	YieldData		If traded on Yield, price must be calculated "to worst" and the <Yield> component block must specify how calculated, redemption date and price (if not par). If traded on Price, the <Yield> component block must specify how calculated - "Worst", and include redemptiondate and price (if not par).
80	AllocQty	x	The quantity being confirmed by this message (this is at a trade level, not block or order level)
854	QtyType
54	Side	x
15	Currency
30	LastMkt
	CpctyConfGrp	x	Indicates number of repeating entries. ** Nested Repeating Group follows **
79	AllocAccount	x	Account number for the trade being confirmed by this message
661	AllocAcctIDSource
798	AllocAccountType
6	AvgPx	x	Gross price for the trade being confirmed Always expressed in percent-of-par for Fixed Income
74	AvgPxPrecision		Absence of this field indicates that default precision arranged by the broker/institution is to be used
423	PriceType		Price type for the AvgPx field
860	AvgParPx
	SpreadOrBenchmarkCurveData		Insert here the set of "SpreadOrBenchmarkCurveData" fields defined in "Common Components of Application Messages"
861	ReportedPx		Reported price (may be different to AvgPx in the event of a marked-up or marked-down principal trade)
58	Text
354	EncodedTextLen
355	EncodedText
81	ProcessCode		Used to identify whether the trade was a soft dollar trade, step in/out etc. Broker of credit, where relevant, can be specified using the Parties nested block above.
381	GrossTradeAmt	x
157	NumDaysInterest
230	ExDate		Optional "next coupon date" for Fixed Income
158	AccruedInterestRate
159	AccruedInterestAmt		Required for Fixed Income products that trade with accrued interest
738	InterestAtMaturity		Required for Fixed Income products that pay lump sum interest at maturity
920	EndAccruedInterestAmt		For repurchase agreements the accrued interest on termination.
921	StartCash		For repurchase agreements the start (dirty) cash consideration
922	EndCash		For repurchase agreements the end (dirty) cash consideration
238	Concession
237	TotalTakedown
118	NetMoney	x
890	MaturityNetMoney		Net Money at maturity if Zero Coupon and maturity value is different from par value
119	SettlCurrAmt
120	SettlCurrency
155	SettlCurrFxRate
156	SettlCurrFxRateCalc
63	SettlType
64	SettlDate
	SettlInstructionsData		Insert here the set of "SettlInstructionsData" fields defined in "Common Components of Application Messages" Used to communicate settlement instructions for this Confirmation.
	CommissionData
858	SharedCommission		Used to identify any commission shared with a third party (e.g. directed brokerage)
	Stipulations
	MiscFeesGrp		Required if any miscellaneous fees are reported. Indicates number of repeating entries. Repeating group. ** Nested Repeating Group follows **
	StandardTrailer	x

Notes

Please post comments, clarifications, examples here. Click on the edit button on the right and away you go! 

Don't forget to refer to the FPL Discussion Groups to back up anything you write.
You will often find the authoritative statements on matters of FIX specification interpretation there.
Links from FIXwiki pages to relevant discussions on the FPL site are very valuable.

For example if you were writing a clarification on how to specify the "quantity" of an order in FIX, you might add the
following relevant link, http://www.fixprotocol.org/discuss/read/f5014573, to back up your points.