AllocationInstruction/FIX.4.2

Message Content of AllocationInstruction (MsgType=J)

TagText	FieldName or ComponentName	Required	Description
	StandardHeader	x	MsgType = J
70	AllocID	x
71	AllocTransType	x
72	RefAllocID		Required for AllocTransType = Calculated, Replace, or Cancel
196	AllocLinkID		Can be used to link two different Allocation messages (each with unique AllocID) together, i.e. for F/X "Netting" or "Swaps"
197	AllocLinkType		Can be used to link two different Allocation messages and identifies the type of link. Required if AllocLinkID is specified.
73	NoOrders		Indicates number of orders to be combined for allocation. If order(s) were manually delivered set to 1 (one).
11	ClOrdID		Order ID assigned by client if order(s) were electronically delivered and executed. If order(s) were manually delivered this field should contain string "MANUAL".
37	OrderID
198	SecondaryOrderID		Can be used to provide order id used by exchange or executing system.
66	ListID		Required for List Orders.
105	WaveNo
124	NoExecs		Indicates number of individual execution repeating group entries to follow. Absence of this field indicates that no individual execution entries are included. Primarily used to support step-outs.
32	LastShares		Number of shares in individual execution. Required if NoExecs > 0
17	ExecID
31	LastPx		Price of individual execution. Required if NoExecs > 0
29	LastCapacity		Can be specified by broker for AllocTransTyp=Calculated
54	Side	x
55	Symbol	x
65	SymbolSfx
48	SecurityID
22	IDSource
167	SecurityType		Must be specified if a Future or Option. If a Future: Symbol, SecurityType, and MaturityMonthYear are required. If an Option: Symbol, SecurityType, MaturityMonthYear, PutOrCall, and StrikePrice are required.
200	MaturityMonthYear		Specifiesthe month and year of maturity. Required if MaturityDay is specified.
205	MaturityDay		Can be used in conjunction with MaturityMonthYear to specify a particular maturity date.
201	PutOrCall		For Options.
202	StrikePrice		For Options.
206	OptAttribute		For Options.
231	ContractMultiplier		For Fixed Income, Convertible Bonds, Derivatives, etc. Note: If used, quantities should be expressed in the "nominal" (e.g. contracts vs. shares) amount.
223	CouponRate		For Fixed Income.
207	SecurityExchange		Can be used to identify the security.
106	Issuer
348	EncodedIssuerLen		Must be set if EncodedIssuer field is specified and must immediately precede it.
349	EncodedIssuer		Encoded (non-ASCII characters) representation of the Issuer field in the encoded format specified via the MessageEncoding field.
107	SecurityDesc
350	EncodedSecurityDescLen		Must be set if EncodedSecurityDesc field is specified and must immediately precede it.
351	EncodedSecurityDesc		Encoded (non-ASCII characters) representation of the SecurityDesc field in the encoded format specified via the MessageEncoding field.
53	Shares	x	Total number of shares allocated to all accounts
30	LastMkt		Market of the executions.
336	TradingSessionID
6	AvgPx	x	For F/X orders, should be the "all-in" rate (spot rate adjusted for forward points).
15	Currency		Currency of AvgPx. Should be the currency of the local market or exchange where the trade was conducted.
74	AvgPrxPrecision		Absence of this field indicates that default precision arranged by the broker/institution is to be used
75	TradeDate	x
60	TransactTime		Date/time when allocation is generated
63	SettlmntTyp		Absence of this field is interpreted as Regular
64	FutSettDate		"Settlement Date". Required with SettlmntTyp other than regular
381	GrossTradeAmt		Expressed in same currency as AvgPx. Sum of (AllocShares * AllocAvgPx or AllocPrice).
118	NetMoney		Expressed in same currency as AvgPx. Sum of AllocNetMoney.
77	OpenClose
58	Text
354	EncodedTextLen		Must be set if EncodedText field is specified and must immediately precede it.
355	EncodedText		Encoded (non-ASCII characters) representation of the Text field in the encoded format specified via the MessageEncoding field.
157	NumDaysInterest		Applicable for Convertible Bonds and fixed income
158	AccruedInterestRate		Applicable for Convertible Bonds and fixed income
78	NoAllocs		Indicates number of allocation groups to follow.
79	AllocAccount		May be the same value as BrokerOfCredit if ProcessCode is step-out or soft-dollar step-out and Institution does not wish to disclose individual account breakdowns to the ExecBroker. Required if NoAllocs > 0. Must be first field in repeating group.
366	AllocPrice		Used when performing "executed price" vs. "average price" allocations (e.g. Japan). AllocAccount plus AllocPrice form a unique Allocs entry. Used in lieu of AllocAvgPx.
80	AllocShares	x
81	ProcessCode
92	BrokerOfCredit		Required if ProcessCode is step-out or soft-dollar step-out
208	NotifyBrokerOfCredit
209	AllocHandlInst
161	AllocText		Free format text field related to this AllocAccount
360	EncodedAllocTextLen		Must be set if EncodedAllocText field is specified and must immediately precede it.
361	EncodedAllocText		Encoded (non-ASCII characters) representation of the AllocText field in the encoded format specified via the MessageEncoding field.
76	ExecBroker		Required for step-in and step-out trades
109	ClientID		Used for firm identification in third-party transactions (should not be a substitute for OnBehalfOfCompID/DeliverToCompID).
12	Commission
13	CommType
153	AllocAvgPx		AvgPx for this AllocAccount. For F/X orders, should be the "all-in" rate (spot rate adjusted for forward points) for this allocation.
154	AllocNetMoney		NetMoney for this AllocAccount ((AllocShares * AllocAvgPx) - Commission - sum of MiscFeeAmt + AccruedInterestAmt) if a Sell ((AllocShares * AllocAvgPx) + Commission + sum of MiscFeeAmt + AccruedInterestAmt) if a Buy
119	SettlCurrAmt		AllocNetMoney in SettlCurrency for this AllocAccount if SettlCurrency is different from "overall" Currency
120	SettlCurrency		SettlCurrency for this AllocAccount if different from "overall" Currency. Required if SettlCurrAmt is specified.
155	SettlCurrFxRate		Foreign exchange rate used to compute SettlCurrAmt from Currency to SettlCurrency
156	SettlCurrFxRateCalc		Specifies whether the SettlCurrFxRate should be multiplied or divided
159	AccruedInterestAmt		Applicable for Convertible Bonds and fixed income
160	SettlInstMode		Type of Settlement Instructions which will be provided via Settlement Instructions message (0=Default, 1=Standing Instructions, 2=Specific Allocation Account Overriding, 3=Specific Allocation Account Standing)
136	NoMiscFees		Required if any miscellaneous fees are reported. Indicates number of repeating entries. Repeating group within Alloc repeating group. ** Nested Repeating Group follows **
137	MiscFeeAmt		Required if NoMiscFees > 0
138	MiscFeeCurr		Required if NoMiscFees > 0
139	MiscFeeType		Required if NoMiscFees > 0
	StandardTrailer	x

Notes

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Don't forget to refer to the FPL Discussion Groups to back up anything you write.
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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.