Line item
A line item is an appropriation that is itemized on a separate line in a budget.
Line item veto The authority of an executive to veto a specific appropriation in a budget passed by a legislature. Viewing the line-item veto as an effective tactic against pork-barrel legislation, presidents Ronald Reagan and George H. W. Bush unsuccessfully sought this authority, which many state governors possess, from Congress. Under current law the president must choose between signing or vetoing the entire budget rather than parts (items on budget lines) of it.
The line-item veto has been desired by most U.S. Presidents, in order to increase the president's control over the enactment of law. The rationale usually given by the executive branch is that the president should have the power to curtail pork barrel spending, or concentrated spending that helps a tiny portion of the country, but is funded by the entire country. This power is held by many state governors in the United States of America.
The President of the United States was briefly granted this power in the Line Item Veto Act of 1996. It was used once before U.S. District Court Judge Thomas Hogan declared it unconstitutional on February 12, 1998. This ruling was subsequently affirmed on June 25, 1998 by a 6-3 decision of the Supreme Court of the United States in the case Clinton v. City of New York.
The Confederate States Constitution of 1861 allowed line item veto.
As of 2005, 43 states allow the line item veto. The exceptions are Indiana, Maryland, Nevada, New Hampshire, North Carolina, Rhode Island, and Vermont.
(source - answers.com)