PreTradeAnonymity (FIX tag 1091)

BooleanFIX 5.0 SP2

PreTradeAnonymity (tag 1091) is a Boolean field defined in FIX 5.0 SP2. It appears in 11 message types, always optionally.

At a glance

Tag: 1091
Name: PreTradeAnonymity
Datatype: Boolean (char)
Dialects: FIX 5.0 SP2
Messages: 11

What the specification says

Allows trader to explicitly request anonymity or disclosure in pre-trade market data feeds. Anonymity is relevant in markets where counterparties are regularly disclosed in order depth feeds. Disclosure is relevant when counterparties are not normally visible.

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

A real message using tag 1091

NewOrderSingle · FIX 5.0 SP2

Tag	Field	Wire value	Meaning
8	BeginString	FIXT.1.1
9	BodyLength	118
35	MsgType	D	NewOrderSingle
49	SenderCompID	BOARTEAM
56	TargetCompID	COUNTERPARTY
34	MsgSeqNum	2
52	SendingTime	20240101-12:00:00.000
11	ClOrdID	ORD-10042
54	Side	1	Buy
60	TransactTime	20240101-12:00:00.000
40	OrdType	1	Market
1091	PreTradeAnonymity	N
10	CheckSum	156

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 5.0 SP2 dictionary and verified at build time: it parses and validates with no issues. Open the decoder to try your own message.

Where tag 1091 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	Requiredness	Where in the message
CrossOrderCancelReplaceRequest	t	Optional	inside the SideCrossOrdModGrp component
ExecutionReport	8	Optional	directly on the message body
MultilegOrderCancelReplace	AC	Optional	directly on the message body
NewOrderCross	s	Optional	inside the SideCrossOrdModGrp component
NewOrderList	E	Optional	inside the ListOrdGrp component
NewOrderMultileg	AB	Optional	directly on the message body
NewOrderSingle	D	Optional	directly on the message body
OrderCancelReplaceRequest	G	Optional	directly on the message body
QuoteRequest	R	Optional	directly on the message body
QuoteRequestReject	AG	Optional	directly on the message body
QuoteResponse	AJ	Optional	directly on the message body

Wire format

Y or N. Not 1/0, and not true/false. @boarteam/fix keeps the value as a string and, for enumerated fields, reports validate/value-not-in-enum when it is not a defined value.

Read tag 1091 in TypeScript

decode.tsts

import { createFixEngine } from "@boarteam/fix";import { dictionary } from "@boarteam/fix-dict-fix50sp2";const fix = createFixEngine(dictionary);const { message, issues } = fix.parse(raw);const field = message.fields[1091];field?.name;   // "PreTradeAnonymity"field?.raw;    // the verbatim wire stringfield?.value;  // coerced to a boolean

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-fix50sp2

Try the decoder Source on GitHub