; or (IV) other dedicated revenue sources that also secure the senior project obligations; and (ii) include a coverage requirement or similar security feature supporting the project obligations; and (B) may have a lien on revenues described in subparagraph (A), subject to any lien securing project obligations. (6) Period of availability The full amount of a line of credit under this section, to the extent not drawn upon, shall be available during the 10-year period beginning on the date of substantial completion of the project. (7) Rights of third-party creditors (A) Against Federal Government A third-party creditor of the obligor shall not have any right against the Federal Government with respect to any draw on a line of credit under this section. (B) Assignment An obligor may assign a line of credit under this section to— (i) one or more lenders; or (ii) a trustee on the behalf of such a lender. (8) Nonsubordination (A) In general Except as provided in subparagraph (B), a direct loan under this section shall not be subordinated to the claims of any holder of project obligations in the event of bankruptcy, insolvency, or liquidation of the obligor. (B) Pre-existing indenture (i) In general The Assistant Secretary shall waive the requirement of subparagraph (A) for a public agency borrower that is financing ongoing capital programs and has outstanding senior bonds under a preexisting indenture, if— (I) the line of credit— (aa) is rated in the A category or higher; or (bb) in the case of a small project, meets an alternative standard that the Assistant Secretary shall establish under section 6 for purposes of this subclause; (II) the BIFIA program loan resulting from a draw on the line of credit is payable from pledged revenues not affected by project performance, such as a tax-backed revenue pledge or a system-backed pledge of project revenues