The NASCAR Sprint Cup Series (often shortened to Sprint Cup or the Cup Series) is the top racing series of the National Association for Stock Car Auto Racing (NASCAR). The series is named for its current sponsor, Sprint Nextel, and has been known by other names in the past. It was originally known as the Strictly Stock Series (1949) and shortly became the Grand National Series (1950_1970). While leasing its naming rights to R. J. Reynolds Tobacco Company, it was known as the Winston Cup Series (1971_2003). A similar deal was made with NEXTEL in 2003, becoming the NEXTEL Cup Series (2004_2007) and it became the Sprint Cup after Sprint acquired NEXTEL in 2005. The name 'Sprint' refers specifically to the corporation of the same name; sprint car racing is a separate racing discipline.