traders will be exempt from aggregation in accordance with the standards set forth in
Commodity Futures Trading Regulation 150.4(d).

{e) (ec) Upon request by the Exchange, any person claiming an exemption from speculative
position limits under this Regulation must provide to the Exchange such information as
specified in the request relating to the positions owned or controlled by that person; trading
done pursuant to the claimed exemption; the futures, options, or cash market positions
which support the claim of the exemption; and the relevant business relationships
supporting a claim of exemption.



July 20, 2006

SL 23 TS 37
Ms. Eileen A. Donovan UP. or ine Scene ARIAT

Acting Secretary

Commodity Futures Trading Commission
Three Lafayette Center

1155 21" Street, N.W.

Washington, D.C. 20581

Reference File # 2701.01
Rule Certification
Dear Ms. Donovan:

Pursuant to Commission Regulation 40.6(a), the Chicago Board of Trade (CBOT®) hereby
submits the following:

- Amendments to CBOT Rulebook Appendix 4C and Regulation 425.05 per
the attached texts (additions underlined, deletions struck through).

These amendments will modify spot month position limits (applicable during the last ten trading
days) for CBOT Treasury futures as indicated below.

Under revised Appendix 4C, the limits for Five-Year Treasury Notes will increase from 35,000
to 45,000 contracts; the limits for Ten-Year Treasury Notes will increase from 50,000 to 60,000
contracts.

Regulation 425.05, as amended, will establish revised aggregation standards for Treasury futures
position limits. In determining compliance with these limits, all positions in accounts for which
the person, by power of attorney or otherwise, directly or indirectly holds positions or controls
trading shall be aggregated, except as otherwise exempted in accordance with amended
Regulation 425.05. The limits also apply to positions held by two or more persons acting
pursuant to an expressed or implied agreement or understanding.

Under the current aggregation standards for Treasury futures position limits, independently
controlled accounts of different legal entities are disaggregated, irrespective of whether the
entities are affiliated, while independently controlled accounts of the same legal entity are
aggregated.

The revised standards maintain the exemption from aggregation for the independently controlled
accounts of separate legal entities. The revised standards also establish new exemptions for
independently controlled accounts of eligible entities, as defined in Commodity Futures Trading
Commission Regulation 150.01(d).


July 20, 2006
Ms. Eileen A. Donovan
Page Two

The CBOT intends to implement these amendments for March 2007 and subsequent contract
months in CBOT Long Term Treasury Bond and Two-Year, Five-Year and Ten-Year Treasury
Note futures.

There were no opposing views among the CBOT Board of Directors concerning these
amendments.

The CBOT certifies that these amendments comply with the Commodity Exchange Act and the
rules thereunder.

Sincerely,

Paul J. Draths
Vice President and Secretary

b071806


Additions underlined; deletions struck through

Appendix 4C

#13 In the last ten trading days of the expiring futures month, the following position limits in the
expiring contract will apply: U.S. Treasury Bonds — 25,000 contracts; U.S. Treasury Notes (6% -
10 Year) — 50,006 60,000 contracts; U.S. Treasury Notes (5 Year) — 35,600 45,000 contracts;
U.S. Treasury Notes (2 Year) — 25,000 contracts. No hedge exemptions will be permitted with
respect to these limits.

425.05 Exemption from Aggregation for Position Limit Purposes

(a)

(b)

(c)

Positions carried for an eligible entity, as defined in Commodity Futures Trading
Commission Regulation 150.1(d), on behalf of customers and in a separate account or
accounts of an independent account controller, as defined in Commodity Futures Trading
Commission Regulation 150.1(e), may exceed the position limits set forth in

Regulation 425.01, to the extent such positions are Treasury futures positions or positions
not for the spot month in any other commodity. However, the overall positions held or
controlled by each such independent account controller may not exceed the limits specified
in Regulation 425.01.

Additional Requirements for Exemption of Affiliated Entities - If the independent account
controller is affiliated with the eligible entity or another independent account controller,
each of the affiliated entities must:

1) Have, and enforce, written procedures to preclude the affiliated entities from having
knowledge of, gaining access to, or receiving data about, trades of the other. Such
procedures must include document routing, and other procedures or security arrangements,
including separate physical locations, which would maintain the independence of their
activities. However, such procedures may provide for the disclosure of information which
is reasonably necessary for an eligible entity to maintain the level of control consistent
with its fiduciary responsibilities and necessary to fulfill its duty to supervise diligently the
trading done on its behalf;

2) Trade such accounts pursuant to separately developed and independent trading systems
and market such trading systems separately; and

3) Solicit funds for such trading by separate Disclosure Documents that meet the standards
of Commodity Futures Trading Commission Regulations 4.24 or 4.34, as applicable.

Additionally, Treasury futures positions carried in independently controlled accounts

(d)

owned by different legal entities, irrespective of whether the entities qualify as eligible
entities, may exceed the position limits set forth in Regulation 425.01 provided that
affiliated legal entities meet the independence standards specified in (b) above and
provided that the overall positions held or controlled by each such independent account
controller may not exceed the limits specified in Regulation 425.01.

Positions held by futures commission merchants or their separately organized affiliates in

customer discretionary accounts or guided account programs controlled by independent