Resend Request Message Fields
| Tag | Field Name | Required | Description |
|---|---|---|---|
| 35 | MsgType | Y | 2 |
| 7 | BeginSeqNo | Y | Sequence number of first message in range to be resent. |
| 16 | EndSeqNo | Y | 0 means + infinity |
A Resend Request message should be processed even if it is received ahead of sequence. Only after resending the requested range (all marked PossDup= Y, including any gap fills) should Resend Request message be issued in the opposite direction.
As discussed in the FIX 4.2 specification, it is possible to send an open or closed sequence range in a Resend Request message (an open range uses sequence zero as the EndSeqNo). Cboe will honor either type of request, but will always issue Resend Request message with a closed sequence range.