31 CFR §601.4
Verified against eCFR.gov as of June 20, 2026View official text on eCFR.gov ↗
The distinctive counterfeit deterrents that may be used in the denominations of United States Federal Reserve notes as prescribed by the Secretary of the Treasury are:
- (a)Security threads containing graphics consisting of the designation “USA” and the denomination of the currency note, expressed in alphabetic or numeric characters.
- (b)Optically variable inks with material characteristics.
- (c)Non-visual characteristic inks with material characteristics.
- (d)Optically variable thread (three-dimensional (3-D) security ribbon and micro-optic stripe) visible in front or back of the currency note.
- (e)Non-visual characteristic features with material characteristics.