This message is used to request a retransmission of a set of one or more messages generated by the application specified in RefApplID (1355). The message can be used for five types of transmission requests:
0 - retransmission of application messages for a specified application and sequence number range,
1 - subscription to an application in order receive, for example, drop copy services,
2 - request for the last application sequence number sent by an application,
3 - request the valid set of application identifiers for which a user is authorized,
4 - unsubscribe to one or more of applications
The Request message specifies the sequence number range using ApplBegSeqNum (1182) and ApplEndSeqNum (1183) for a given RefApplID (1355) to request messages for retransmission.