(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[supreg].
(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[supreg]; and
(2) definitive Series I savings bonds that have been converted to book-entry bonds through TreasuryDirect[supreg]. [70 FR 14942, Mar. 23, 2005]