Basic, substantive legislation that establishes or continues the legal operation of a federal programme or agency, either indefinitely or for a specific period of time, or which sanctions a particular type of obligation or expenditure. An authorization normally is a prerequisite for an appropriation or other kind of budget authority. Under the rules of both houses, the appropriation for a programme or agency may not be considered until its authorization has been considered. An authorization also may limit the amount of budget authority to be provided or may authorise the appropriation of "such sums as may be necessary."