The Security Definition <d> message is used for the following:
Identifier for the Security Definition <d> message
Response to the Security Definition Request <c>
Insert here the set of "<Instrument>" (symbology) fields of the requested Security
Comment, instructions, or other identifying information.
Must be set if EncodedText <355> field is specified and must immediately precede it.
Encoded (non-ASCII characters) representation of the Text <58> field in the encoded format specified via the MessageEncoding <347> field.
Number of legs that make up the Security
Insert here the set of "<InstrumentLeg>" (leg-specific symbology) fields