| Tag | 
                              Field Name | 
                              Req'd | 
                              Comments | 
                           
                           
                              | 
                                    Component Block - <StandardHeader> | 
                              Y | 
                              MsgType = w  (lowercase W) | 
                           
                           
                              | 320 | 
                              SecurityReqID | 
                              Y | 
                               | 
                           
                           
                              | 322 | 
                              SecurityResponseID | 
                              Y | 
                              Identifier for the security response message | 
                           
                           
                              | 323 | 
                              SecurityResponseType | 
                              Y | 
                              The result of the security request identified by SecurityReqID | 
                           
                           
                              | 557 | 
                              TotNoSecurityTypes | 
                              N | 
                              Indicates total number of security types in the event that multiple Security Type messages are used to return results | 
                           
                           
                              | 893 | 
                              LastFragment | 
                              N | 
                              Indicates whether this is the last fragment in a sequence of message fragments. Only required where message has been fragmented. | 
                           
                           
                              | 
                                    Component Block - <SecTypesGrp> | 
                              N | 
                               | 
                           
                           
                              | 58 | 
                              Text | 
                              N | 
                              Comment, instructions, or other identifying information. | 
                           
                           
                              | 354 | 
                              EncodedTextLen | 
                              N | 
                              Must be set if EncodedText field is specified and must immediately precede it. | 
                           
                           
                              | 355 | 
                              EncodedText | 
                              N | 
                              Encoded (non-ASCII characters) representation of the Text field in the encoded format specified via the MessageEncoding field. | 
                           
                           
                              | 336 | 
                              TradingSessionID | 
                              N | 
                              Optional Trading Session Identifier to specify a particular trading session for which you want to obtain a list of securities
                                 that are tradeable.
                               | 
                           
                           
                              | 625 | 
                              TradingSessionSubID | 
                              N | 
                               | 
                           
                           
                              | 263 | 
                              SubscriptionRequestType | 
                              N | 
                              Subscribe or unsubscribe for security status to security specified in request. | 
                           
                           
                              | 1301 | 
                              MarketID | 
                              N | 
                              Optional MarketID to specify a particular trading session for which you want to obtain a list of securities that are tradeable. | 
                           
                           
                              | 1300 | 
                              MarketSegmentID | 
                              N | 
                              Optional Market Segment Identifier to specify a particular trading session for which you want to obtain a list of securities
                                 that are tradeable.
                               | 
                           
                           
                              | 
                                    Component Block - <ApplicationSequenceControl> | 
                              N | 
                               | 
                           
                           
                              | 
                                    Component Block - <StandardTrailer> | 
                              Y | 
                               |