EncodedSecurityDescLen (FIX tag 350)

LengthFIX 4.4FIX 4.2FIX 5.0 SP2

EncodedSecurityDescLen (tag 350) is a Length field defined in FIX 4.4, FIX 4.2 and FIX 5.0 SP2. It appears in 59 message types, always optionally.

At a glance

Tag: 350
Name: EncodedSecurityDescLen
Datatype: Length (int)
Dialects: FIX 4.4, FIX 4.2 and FIX 5.0 SP2
Messages: 59

What the specification says

FIX 4.4

Byte length of encoded (non-ASCII characters) EncodedSecurityDesc (35) field.

FIX 4.2

Byte length of encoded (non-ASCII characters) EncodedSecurityDesc field.

FIX 5.0 SP2

Byte length of encoded (non-ASCII characters) EncodedSecurityDesc (351) field.

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

A real message using tag 350

NewOrderSingle · FIX 4.4

Tag	Field	Wire value	Meaning
8	BeginString	FIX.4.4
9	BodyLength	117
35	MsgType	D	Order – Single
49	SenderCompID	BOARTEAM
56	TargetCompID	COUNTERPARTY
34	MsgSeqNum	2
52	SendingTime	20240101-12:00:00.000
11	ClOrdID	ORD-10042
350	EncodedSecurityDescLen	7
54	Side	1	Buy
60	TransactTime	20240101-12:00:00.000
40	OrdType	1	Market
10	CheckSum	003

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 350 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.

Message	MsgType	FIX 4.4	FIX 4.2	FIX 5.0 SP2	Where in the message
AdjustedPositionReport	BL	—	—	Optional	inside InstrmtGrp › Instrument
Advertisement	7	Conditional	Optional	Optional	inside the Instrument component
AllocationInstruction	J	Conditional	Optional	Optional	inside the Instrument component
AllocationInstructionAlert	BM	—	—	Optional	inside the Instrument component
AllocationReport	AS	Conditional	—	Optional	inside the Instrument component
AssignmentReport	AW	Conditional	—	Optional	inside the Instrument component
CollateralAssignment	AY	Conditional	—	Optional	inside the Instrument component
CollateralInquiry	BB	Conditional	—	Optional	inside the Instrument component
CollateralInquiryAck	BG	Conditional	—	Optional	inside the Instrument component
CollateralReport	BA	Conditional	—	Optional	inside the Instrument component
CollateralRequest	AX	Conditional	—	Optional	inside the Instrument component
CollateralResponse	AZ	Conditional	—	Optional	inside the Instrument component
Confirmation	AK	Conditional	—	Optional	inside the Instrument component
ContraryIntentionReport	BO	—	—	Optional	inside the Instrument component
CrossOrderCancelReplaceRequest	t	Conditional	—	Optional	inside the Instrument component
CrossOrderCancelRequest	u	Conditional	—	Optional	inside the Instrument component
DerivativeSecurityList	AA	Conditional	—	Optional	inside RelSymDerivSecGrp › Instrument
DerivativeSecurityListUpdateReport	BR	—	—	Optional	inside RelSymDerivSecUpdGrp › Instrument
DontKnowTrade	Q	Conditional	Optional	Optional	inside the Instrument component
Email	C	Conditional	Optional	Optional	inside InstrmtGrp › Instrument
ExecutionAcknowledgement	BN	—	—	Optional	inside the Instrument component
ExecutionReport	8	Conditional	Optional	Optional	inside the Instrument component
IOI	6	Conditional	Optional	Optional	inside the Instrument component
ListStrikePrice	m	Conditional	Optional	Optional	inside InstrmtStrkPxGrp › Instrument
MarketDataIncrementalRefresh	X	Conditional	Optional	Optional	inside MDIncGrp › Instrument
MarketDataRequest	V	Conditional	Optional	Optional	inside InstrmtMDReqGrp › Instrument
MarketDataSnapshotFullRefresh	W	Conditional	Optional	Optional	inside the Instrument component
MassQuote	i	Conditional	Optional	Optional	inside QuotSetGrp › QuotEntryGrp › Instrument
MassQuoteAcknowledgement	b	Conditional	Optional	Optional	inside QuotSetAckGrp › QuotEntryAckGrp › Instrument
MultilegOrderCancelReplace	AC	Conditional	—	Optional	inside the Instrument component
NewOrderCross	s	Conditional	—	Optional	inside the Instrument component
NewOrderList	E	Conditional	Optional	Optional	inside ListOrdGrp › Instrument
NewOrderMultileg	AB	Conditional	—	Optional	inside the Instrument component
NewOrderSingle	D	Conditional	Optional	Optional	inside the Instrument component
News	B	Conditional	Optional	Optional	inside InstrmtGrp › Instrument
OrderCancelReplaceRequest	G	Conditional	Optional	Optional	inside the Instrument component
OrderCancelRequest	F	Conditional	Optional	Optional	inside the Instrument component
OrderMassActionReport	BZ	—	—	Optional	inside the Instrument component
OrderMassActionRequest	CA	—	—	Optional	inside the Instrument component
OrderMassCancelReport	r	Conditional	—	Optional	inside the Instrument component
OrderMassCancelRequest	q	Conditional	—	Optional	inside the Instrument component
OrderMassStatusRequest	AF	Conditional	—	Optional	inside the Instrument component
OrderStatusRequest	H	Conditional	Optional	Optional	inside the Instrument component
PositionMaintenanceReport	AM	Conditional	—	Optional	inside the Instrument component
PositionMaintenanceRequest	AL	Conditional	—	Optional	inside the Instrument component
PositionReport	AP	Conditional	—	Optional	inside the Instrument component
Quote	S	Conditional	Optional	Optional	inside the Instrument component
QuoteCancel	Z	Conditional	Optional	Optional	inside QuotCxlEntriesGrp › Instrument
QuoteRequest	R	Conditional	Optional	Optional	inside QuotReqGrp › Instrument
QuoteRequestReject	AG	Conditional	—	Optional	inside QuotReqRjctGrp › Instrument
QuoteResponse	AJ	Conditional	—	Optional	inside the Instrument component
QuoteStatusReport	AI	Conditional	—	Optional	inside the Instrument component
QuoteStatusRequest	a	Conditional	Optional	Optional	inside the Instrument component
RFQRequest	AH	Conditional	—	Optional	inside RFQReqGrp › Instrument
RequestForPositions	AN	Conditional	—	Optional	inside the Instrument component
RequestForPositionsAck	AO	Conditional	—	Optional	inside the Instrument component
SecurityDefinition	d	Conditional	Optional	Optional	inside the Instrument component
SecurityDefinitionRequest	c	Conditional	Optional	Optional	inside the Instrument component
SecurityDefinitionUpdateReport	BP	—	—	Optional	inside the Instrument component
SecurityList	y	Conditional	—	Optional	inside SecListGrp › Instrument
SecurityListRequest	x	Conditional	—	Optional	inside the Instrument component
SecurityListUpdateReport	BK	—	—	Optional	inside SecLstUpdRelSymGrp › Instrument
SecurityStatus	f	Conditional	Optional	Optional	inside the Instrument component
SecurityStatusRequest	e	Conditional	Optional	Optional	inside the Instrument component
SettlementObligationReport	BQ	—	—	Optional	inside SettlObligationInstructions › Instrument
StreamAssignmentReport	CD	—	—	Optional	inside StrmAsgnRptGrp › StrmAsgnRptInstrmtGrp › Instrument
StreamAssignmentRequest	CC	—	—	Optional	inside StrmAsgnReqGrp › StrmAsgnReqInstrmtGrp › Instrument
TradeCaptureReport	AE	Conditional	—	Optional	inside the Instrument component
TradeCaptureReportAck	AR	Conditional	—	Optional	inside the Instrument component
TradeCaptureReportRequest	AD	Conditional	—	Optional	inside the Instrument component
TradeCaptureReportRequestAck	AQ	Conditional	—	Optional	inside the Instrument component
TradingSessionStatus	h	—	—	Optional	inside the Instrument component

Wire format

A byte count for the length-prefixed field that follows it. Count bytes, not characters — a multi-byte UTF-8 value makes the two differ. @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 350 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);const field = message.fields[350];field?.name;   // "EncodedSecurityDescLen"field?.raw;    // the verbatim wire stringfield?.value;  // coerced to a number

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

Try the decoder Source on GitHub