Hi @didier.nadeau

RDM_UPD_EVENT_TYPE_CORRECTION means the update message contains a correction to previously delivered data.

You will receive this update message when there are previous updates that need correction; i.e. the update was canceled.

Please note that this type of update message is usually sent from the exchange and the behavior may differ for different exchanges.

So, for example; RIC <GNC.AX> have one correction message on 23/07/2018

GNC.AX,Market Price,2018-07-23T04:28:48.441316048Z,+10,Raw,UPDATE,CORRECTION,,,,217,,10718,,25
,,,,FID,32743,,ACVOL_UNS,2125193,
,,,,FID,32,,ACVOL_1,2125193,
,,,,FID,100,,TURNOVER,15787023,
,,,,FID,32741,,TRNOVR_UNS,15787023,
,,,,FID,7584,,VWAP_TOT,7.428513,
,,,,FID,373,,IRGVOL,2518542,
,,,,FID,374,,IRGCOND,1009,009
,,,,FID,3876,,OFFBK_VOL,251842,
,,,,FID,3131,,IRGFID,251842,
,,,,FID,6588,,REPORT_VOL,251842,
,,,,FID,999,,GEN_VAL4,7.445,
,,,,FID,6217,,TRAN_PRICE,7.445,
,,,,FID,1021,,SEQNUM,280163,
,,,,FID,1023,,PRNTBCK,1440279576,
,,,,FID,1003,,GV4_TEXT,C*S3XT,
,,,,FID,6583,,CAN_PRC,7.445,
,,,,FID,6586,,CAN_COND_N,S3XT,
,,,,FID,6584,,CAN_VOL,2518542,
,,,,FID,6587,,CAN_TRD_ID,1440279576,
,,,,FID,6625,,CTRDTIM,04:27:47.000000000,
,,,,FID,6624,,CTRDTIM_MS,16067904,
,,,,FID,6775,,CAN_DATE,2018-07-23,
,,,,FID,6946,,CAN_SEQNO,280163,
,,,,FID,5,,TIMACT,04:28:48.000000000,
,,,,FID,4148,,TIMACT_MS,16128323,

The correction update has a few general information fields, but the field that you should be looking for is FID 6587 [CAN_TRD_ID] which is the trade id number of a canceled or corrected trade event. We can use this number to trace back to the previous update that has the same number.

Again, the behavior may differ for different exchanges. Please contact the content specialist on My Account Contact Us for a specific exchange.