Available receipts are special or trust fund receipts that, pursuant to law, are available as appropriations to a single agency for expenditure without further congressional action. In some fund accounts, use is restricted to investment only or is precluded by a limitation or benefit formula. An available receipt account carries the same symbolization as its corresponding expenditure account, except that an “X” is inserted to indicate the period of availability of such funds for obligation. However, in special circumstances involving dedicated collections for current year obligations and expenditures, these funds are placed in an unavailable receipt account until the Bureau of the Fiscal Service prepares a warrant to move the funds to a current fiscal year expenditure account.