The Security Definition message is used for the following:
1. Accept the security defined in a Security Definition message.
2. Accept the security defined in a Security Definition message with changes to the definition and/or identity of the security.
3. Reject the security requested in a Security Definition message.
4. Respond to a request for securities within a specified market segment.
5. Convey comprehensive security definition for all market segments that the security participates in.
6. Convey the security’s trading rules that differ from default rules for the market segment.

Added in protocol FIX.4.2

See in: FIX.4.2, FIX.4.3, FIX.4.4, FIX.5.0SP1, FIX.5.0SP2, FIX.5.0SP2 EP240.

Field or Component Name Description Is Required Added Is Deprecated
Block StandardHeader MsgType = d (lowercase) Y FIX.4.2
964 SecurityReportID Identifier for Security Definition message FIX.4.4
715 ClearingBusinessDate FIX.4.4
320 SecurityReqID FIX.4.2
322 SecurityResponseID Identifier for the Security Definition message FIX.4.2
323 SecurityResponseType Response to the Security Definition Request FIX.4.2
Block Instrument Insert here the set of “Instrument” (symbology) fields defined in “Common Components of Application Messages”
of the requested Security
FIX.4.3
Block InstrumentExtension Insert here the set of “InstrumentExtension” fields defined in “Common Components of Application Messages” FIX.4.4
OptimisedImplicitBlockRepeating UndInstrmtGrp Number of underlyings FIX.4.4
15 Currency FIX.4.2
336 TradingSessionID FIX.4.2
625 TradingSessionSubID FIX.4.3
58 Text Comment, instructions, or other identifying information. FIX.4.2
354 EncodedTextLen Must be set if EncodedText (355) field is specified and must immediately precede it. FIX.4.2
355 EncodedText Encoded (non-ASCII characters) representation of the Text (58) field in the encoded format specified via the MessageEncoding (347) field. FIX.4.2
OptimisedImplicitBlockRepeating InstrmtLegGrp Number of legs that make up the Security FIX.4.4
827 ExpirationCycle FIX.4.4
561 RoundLot FIX.4.3
562 MinTradeVol FIX.4.3
Block StandardTrailer Y FIX.4.2