boxcar bill
n.— «Often members of both parties’ leadership introduce what’s called “boxcar” bills—bills with general titles, like “tax changes”—that contain no text. They are introduced just in case, at the end of a session, the bill file is needed for last-minute action.» —“Rating the legislators: How we did it” Deseret Morning News (Salt Lake City, Utah) Mar. 26, 2006. (source: Double-Tongued Dictionary)