Section 363.4 - How is TreasuryDirect®different from the Legacy Treasury Direct®system and the commercial book-entry system?(a)TreasuryDirect. TreasuryDirect is a book-entry, online system maintained by Treasury for purchasing, holding and conducting permitted transactions in eligible Treasury securities in electronic form as a computer record on the books of Treasury. TreasuryDirect currently provides for the purchase and holding of eligible book-entry savings bonds, zero-percent certificates of indebtedness, and eligible marketable Treasury securities.(b)Legacy Treasury Direct. The Legacy Treasury Direct system is a non-Internet-based book-entry system maintained by Treasury for holding and conducting permitted transactions in eligible marketable Treasury securities as book-entry products. The terms and conditions for the Legacy Treasury Direct system are found at 31 CFR part 357 , subpart C.(c)Commercial book-entry system. The commercial book-entry system is the book-entry system in which Treasury securities are held in a tiered system through securities intermediaries such as financial institutions or brokerage firms. The regulations governing the commercial book-entry system are found at 31 CFR part 357 , subpart B, and may be referred to in that part as Treasury/Reserve Automated Debt Entry System (TRADES).70 FR 57442, Sept. 30, 2005, as amended at 76 FR 18064, Apr. 1, 2011