March 20, 2017

By Electronic SubmissionMr. Chris Kirkpatrick

Secretary

Commodity Futures Trading Commission

1155 21st Street, N.W.

Washington, D.C. 20581

DDR Rule Filing: DDRO6Re: Amendments to DTCC Data Repository (U.S.) LLC Rulebook Pursuant to Section 5c(c)

(1) of the Commodity Exchange Act and Commission Regulation § 40.6

Dear Mr. Kirkpatrick:

Pursuant to Section 5c(c)( 1) of the Commodity Exchange Act, as amended, and Commodity FuturesTrading Commission (the “Commission” or “CFTC”) Regulation § 40.6, DTCC Data Repository

(U.S.) LLC (“DDR”) submits, by written certification, amendments to the DTCC Data Repository

(U.S.) LLC Rulebook (“DDR Rulebook”), including, but not limited to, the changes enumerated

below.

I. DDR has amended the cover page ofthe DDR Rulebook to update the effective date.

II. DDR has amended DDR Rulebook Section 1.1 to clarify that Users may be required to

execute additional membership documentation, beyond the User Agreement, to obtain access

to DDR’s SDR Services.

III. DDR has amended DDR Rulebook Section 1.2 to clarify that Users are subject to all

Applicable Law including Applicable Regulations relevant to the User or the transaction

associated with such User.

IV. DDR has amended DDR Rulebook Section 1.3 to clarify current practices related to the

ability of Users to view paper confirmations (if any exist).
Action Relief Letters and to remove the specific requirements of the exceptions orexemptions to clearing in order to streamline the description ofthe requirements.

VII. DDR has amended DDR Rulebook Section 4.2 to clarify that the DDR System will check

each USI received to ensure that the USI is well-formed (e.g., use of namespace) and that the

identifier has not been previously used between the two counterparties and to clarify that

DDR will only assign a USI for Canadian submissions if requested to do so.

VIII. DDR has amended DDR Rulebook Section 4.3 to remove the reference to GMEI, a specific

LEI Issuer and to clarify that each User that is a Reporting Party must provide an LEI.

IX. DDR has amended DDR Rulebook Section 4.5 to define EID as an Event Identifier and to

clarify that DDR will validate that any new event message for a given UTI, in addition toUSI, has a new unique EID for that submitter.

X. DDR has amended DDR Rulebook Section 5.1.2 to clarify and provide guidance on the

submission guidelines related to Canadian Public Price Dissemination requirements.

XI. DDR has amended DDR Rulebook Section 5.1.3 to clarify that the restriction on disclosing

the identity of a party to the swap also applies to a security-based swap.

XII. DDR has amended DDR Rulebook Section 5.3 to clarify that DDR calculates whether a

specified swap qualifies as a block trade pursuant to CFTC Part 43 based upon Userindication in its message submission, for certain asset classes.

XIII. DDR has amended DDR Rulebook Section 5.5 to clarify that DDR will make transaction

level reports of aggregated transactions available to the public pursuant to the Canadian

Regulations.

XIV. DDR has amended DDR Rulebook Section 6.3 to clarify that DDR will not make commercial

use of real-time swap data prior to its public dissemination.

XV. DDR has amended DDR Rulebook Section 7.1 to provide an explanation of how

unscheduled system downtime impacts the dissemination and receipt of information.
XVIII. DDR has amended DDR Rulebook Section 10.1.2 to clarify how Users can access trade

detail reports in the event of dispute between Users.

XIX. DDR has amended DDR Rulebook Section 10.2 to add language confirming that DDR will

promptly notify all Designated Regulators should an Applicant be denied access to SDR

Services, or limited in respect of access to services offered, directly or indirectly.

XX. DDR has amended DDR Rulebook Section 10.3.1 to clarify that DDR can recommend

termination of a User to the Board for failure to pay fees when due.

XXI. DDR has amended DDR Rulebook Section 11.1 to include a description of the DDR

Conflicts of Interest Resolution Process.

XXII. DDR has amended DDR Rulebook Section 12 to include additional Canadian regulators in

the definition of Canadian Regulators, to eliminate specific references to individual Canadian

regulators, and to add or update definitions including: Applicable Publications, CFTCRegulations. DDR System, MSBSP, PPD, Reporting Party. SBSD, SEC Regulations andTransaction Record.

XXIII. DDR has amended DDR Rulebook Appendix A to remove the Repository User Agreement

for Qualified Multilateral Trading Facilities.

XXIV. DDR has amended DDR Rulebook Appendix B to include additional Canadian regulators in

the Canadian Repository Appendix to the Operating Procedures.

XXV. DDR has amended DDR Rulebook Appendix C to include Canada specific references in the

Privacy Policy.

In addition to the changes described above, additional minor edits have been made throughout theDDR Rulebook. Any material modifications to the DDR Rulebook, including the DDR Operating

Procedures, outlined in this letter have been approved by the DDR Board pursuant to DDR

Operating Procedures Important Legal Information Section 3 Notices.

DDR certifies that these amendments comply with the Commodity Exchange Act and the rules and

regulations promulgated by the Commission thereunder. No substantive opposing views have been
As noted above, enclosed with this letter is a marked version of the DDR Rulebook and DDR

Operating Procedures. If you have any questions or need further information, please contact me at

813 470-1447.

Sincerely, z)

KRomtgDirector and Assistant General Counsel

Enclosures

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