NoLegSecurityAltID (FIX tag 604)

NumInGroupFIX 4.4group counter

NoLegSecurityAltID (tag 604) is a NumInGroup field defined in FIX 4.4. It appears in 50 message types, always optionally. Its datatype is NumInGroup, which makes it a repeating-group counter: its value is the number of entries that follow, not a quantity in its own right.

At a glance

Tag
604
Name
NoLegSecurityAltID
Datatype
NumInGroup (int)
Dialects
FIX 4.4
Messages
50

What the specification says

Multileg instrument's individual security’s NoSecurityAltID. See NoSecurityAltID (454) field for description

Descriptions are quoted from the FIX Orchestra sources under the Apache 2.0 licence.

A real message using tag 604

ExecutionReport · FIX 4.4
TagFieldWire valueMeaning
8BeginStringFIX.4.4
9BodyLength181
35MsgType8Execution Report
49SenderCompIDBOARTEAM
56TargetCompIDCOUNTERPARTY
34MsgSeqNum2
52SendingTime20240101-12:00:00.000
37OrderIDORD-10042
17ExecIDEXEC-88117
150ExecType0New
39OrdStatus0New
54Side1Buy
151LeavesQty0
14CumQty1000000
6AvgPx1.09215
555NoLegs1 entry1repeating group
600LegSymbolEXAMPLE
604NoLegSecurityAltID2 entries2repeating group
605LegSecurityAltIDEXAMPLE
605LegSecurityAltIDEXAMPLE
10CheckSum222
Edit and decode it yourself

Shown with | separators for readability. On the wire FIX uses SOH (0x01), an invisible control byte — and because BodyLength and CheckSum are computed over the actual bytes, the two forms have different checksums. Both are valid and both decode here.

Open in the full decoder →

Generated from the FIX 4.4 dictionary and verified at build time: it parses and validates with no issues. Open the decoder to try your own message.

Where tag 604 appears

Requiredness is a property of the message, not of the field: the same tag can be optional in one message and conditionally required in another.

MessageMsgTypeRequirednessWhere in the message
Advertisement7Optionalinside InstrmtLegGrp › InstrumentLeg › LegSecAltIDGrp
AllocationInstructionJOptionalinside InstrmtLegGrp › InstrumentLeg › LegSecAltIDGrp
AllocationReportASOptionalinside InstrmtLegGrp › InstrumentLeg › LegSecAltIDGrp
AssignmentReportAWOptionalinside InstrmtLegGrp › InstrumentLeg › LegSecAltIDGrp
CollateralAssignmentAYOptionalinside InstrmtLegGrp › InstrumentLeg › LegSecAltIDGrp
CollateralInquiryBBOptionalinside InstrmtLegGrp › InstrumentLeg › LegSecAltIDGrp
CollateralInquiryAckBGOptionalinside InstrmtLegGrp › InstrumentLeg › LegSecAltIDGrp
CollateralReportBAOptionalinside InstrmtLegGrp › InstrumentLeg › LegSecAltIDGrp
CollateralRequestAXOptionalinside InstrmtLegGrp › InstrumentLeg › LegSecAltIDGrp
CollateralResponseAZOptionalinside InstrmtLegGrp › InstrumentLeg › LegSecAltIDGrp
ConfirmationAKOptionalinside InstrmtLegGrp › InstrumentLeg › LegSecAltIDGrp
CrossOrderCancelReplaceRequesttOptionalinside InstrmtLegGrp › InstrumentLeg › LegSecAltIDGrp
CrossOrderCancelRequestuOptionalinside InstrmtLegGrp › InstrumentLeg › LegSecAltIDGrp
DerivativeSecurityListAAOptionalinside RelSymDerivSecGrp › InstrmtLegGrp › InstrumentLeg › LegSecAltIDGrp
DontKnowTradeQOptionalinside InstrmtLegGrp › InstrumentLeg › LegSecAltIDGrp
EmailCOptionalinside InstrmtLegGrp › InstrumentLeg › LegSecAltIDGrp
ExecutionReport8Optionalinside InstrmtLegExecGrp › InstrumentLeg › LegSecAltIDGrp
IOI6Optionalinside InstrmtLegIOIGrp › InstrumentLeg › LegSecAltIDGrp
MarketDataIncrementalRefreshXOptionalinside MDIncGrp › InstrmtLegGrp › InstrumentLeg › LegSecAltIDGrp
MarketDataRequestVOptionalinside InstrmtMDReqGrp › InstrmtLegGrp › InstrumentLeg › LegSecAltIDGrp
MarketDataSnapshotFullRefreshWOptionalinside InstrmtLegGrp › InstrumentLeg › LegSecAltIDGrp
MassQuoteiOptionalinside QuotSetGrp › QuotEntryGrp › InstrmtLegGrp › InstrumentLeg › LegSecAltIDGrp
MassQuoteAcknowledgementbOptionalinside QuotSetAckGrp › QuotEntryAckGrp › InstrmtLegGrp › InstrumentLeg › LegSecAltIDGrp
MultilegOrderCancelReplaceACOptionalinside LegOrdGrp › InstrumentLeg › LegSecAltIDGrp
NewOrderCrosssOptionalinside InstrmtLegGrp › InstrumentLeg › LegSecAltIDGrp
NewOrderMultilegABOptionalinside LegOrdGrp › InstrumentLeg › LegSecAltIDGrp
NewsBOptionalinside InstrmtLegGrp › InstrumentLeg › LegSecAltIDGrp
PositionMaintenanceReportAMOptionalinside InstrmtLegGrp › InstrumentLeg › LegSecAltIDGrp
PositionMaintenanceRequestALOptionalinside InstrmtLegGrp › InstrumentLeg › LegSecAltIDGrp
PositionReportAPOptionalinside InstrmtLegGrp › InstrumentLeg › LegSecAltIDGrp
QuoteSOptionalinside LegQuotGrp › InstrumentLeg › LegSecAltIDGrp
QuoteCancelZOptionalinside QuotCxlEntriesGrp › InstrmtLegGrp › InstrumentLeg › LegSecAltIDGrp
QuoteRequestROptionalinside QuotReqGrp › QuotReqLegsGrp › InstrumentLeg › LegSecAltIDGrp
QuoteRequestRejectAGOptionalinside QuotReqRjctGrp › QuotReqLegsGrp › InstrumentLeg › LegSecAltIDGrp
QuoteResponseAJOptionalinside LegQuotGrp › InstrumentLeg › LegSecAltIDGrp
QuoteStatusReportAIOptionalinside LegQuotStatGrp › InstrumentLeg › LegSecAltIDGrp
QuoteStatusRequestaOptionalinside InstrmtLegGrp › InstrumentLeg › LegSecAltIDGrp
RFQRequestAHOptionalinside RFQReqGrp › InstrmtLegGrp › InstrumentLeg › LegSecAltIDGrp
RequestForPositionsANOptionalinside InstrmtLegGrp › InstrumentLeg › LegSecAltIDGrp
RequestForPositionsAckAOOptionalinside InstrmtLegGrp › InstrumentLeg › LegSecAltIDGrp
SecurityDefinitiondOptionalinside InstrmtLegGrp › InstrumentLeg › LegSecAltIDGrp
SecurityDefinitionRequestcOptionalinside InstrmtLegGrp › InstrumentLeg › LegSecAltIDGrp
SecurityListyOptionalinside SecListGrp › InstrmtLegSecListGrp › InstrumentLeg › LegSecAltIDGrp
SecurityListRequestxOptionalinside InstrmtLegGrp › InstrumentLeg › LegSecAltIDGrp
SecurityStatusfOptionalinside InstrmtLegGrp › InstrumentLeg › LegSecAltIDGrp
SecurityStatusRequesteOptionalinside InstrmtLegGrp › InstrumentLeg › LegSecAltIDGrp
TradeCaptureReportAEOptionalinside TrdInstrmtLegGrp › InstrumentLeg › LegSecAltIDGrp
TradeCaptureReportAckAROptionalinside TrdInstrmtLegGrp › InstrumentLeg › LegSecAltIDGrp
TradeCaptureReportRequestADOptionalinside InstrmtLegGrp › InstrumentLeg › LegSecAltIDGrp
TradeCaptureReportRequestAckAQOptionalinside InstrmtLegGrp › InstrumentLeg › LegSecAltIDGrp

Wire format

The number of entries in the repeating group that follows. The next field on the wire is the group's delimiter tag. @boarteam/fix parses the value as a number and reports parse/invalid-int when it does not lex as one; the raw string is kept either way.

Read tag 604 in TypeScript

decode.tsts
import { createFixEngine } from "@boarteam/fix";import { dictionary } from "@boarteam/fix-dict-fix44";const fix = createFixEngine(dictionary);const { message, issues } = fix.parse(raw);// NoLegSecurityAltID is a group counter, so the entries live on message.groups —// NOT on message.fields. message.fields[604] is undefined.const entries = message.groups[604] ?? [];for (const entry of entries) {  // entry.fields is keyed by tag; entry.groups holds nested groups}

Other NumInGroup fields

Decode this in your own code

The same engine that produced the decoded example above is an Apache-2.0 npm package with zero runtime dependencies. It runs in Node and in the browser, and parse() returns problems as data instead of throwing.

npm i @boarteam/fix @boarteam/fix-dict-fix44