This advisory notice provides links to the TREX layout that will be used by CBOT and CME when the Common Clearing Link is implemented on November 24^th, has been updated by the addition of a new field on the A4 block for electronically-executed trades.  This field is called the Customer Order Reference, and it is an up-to-fourteen byte value in positions 64 through 77, which were formerly filler.  For e-cbot trades, this field is available when submitting orders to help identify the order to the customer or client.

In addition, we have clarified the description of the Electronic Trading User ID field in bytes 48 through 63 on the A4 block, to indicate that for e-cbot trades this is a value from four to eleven bytes long which identifies the specific trader if there is more than one sharing an ITM.

Also, in the description of the Card/Order ID field in bytes 122 through 129 of the Main Block, we have added language clarifying that for trades executed on GLOBEX, this field holds the full eight-byte Trade Order Number (TON number).

Given these changes, we have changed the version number on the document from 1.8 to 1.9.