CFR > Title 31 - Money and Finance: Treasury > SUBTITLE B—Regulations Relating to Money and Finance > CHAPTER II—FISCAL SERVICE, DEPARTMENT OF THE TREASURY (parts 200 to 391) > SUBCHAPTER B—BUREAU OF THE PUBLIC DEBT (parts 306 to 391) > PART 306—GENERAL REGULATIONS GOVERNING U.S. SECURITIES > SUBPART O—Book-Entry Procedure (§306.115 to §306.117)