Section 360.0 - Applicability(a) The regulations in this part apply to definitive (paper) Series I savings bonds that have not been converted to book-entry bonds through TreasuryDirect®.(b) The regulations in 31 CFR part 363 apply to:(1) book-entry Series I savings bonds that were originally issued as book-entry bonds in TreasuryDirect®; and(2) definitive Series I savings bonds that have been converted to book-entry bonds through TreasuryDirect®. 70 FR 14942 , Mar. 23, 2005