10 U.S.C. § 8631 — Accounting for expenditures for obtaining information

This section covers how the Navy accounts for money it spends gathering information from anywhere in the world. If the Secretary of the Navy decides a particular expenditure can be made public, it must be accounted for specifically, like normal government spending. But if the Secretary decides an expenditure should stay secret, normal itemized accounting isn't required. Instead, the Secretary simply signs a certificate stating the amount spent. That signed certificate, by itself, counts as sufficient proof — a "voucher" — that the money was actually spent, without revealing what it was spent on.