(2) United States Government securities at market value. (An escrow account is not required if an individual surety offers Government securities held in book entry form at a depository institution. In lieu thereof, the individual shall provide evidence that the depository institution has—

(i) Placed a notation against the individual’s book entry account indicating that the security has been pledged in favor of the respective agency;

(ii) Agreed to notify the agency prior to maturity of the security; and

(iii) Agreed to hold the proceeds of the security subject to the pledge in favor of the agency until a substitution of securities is made or the security interest is formally released by the agency.);