If Stockholm Open
In 1969-1989 the tournament was a part of the Grand Prix Circuit. From 1990 to 1994 the tournament was a part of Championship Series, Single Week (now - ATP World Tour Masters 1000). From 1995 to 1999 tennis tournament in Stockholm was a part of World Series (now - ATP World 250 series). From 2000 to 2008 the tournament was a part of International Series (now - ATP World 250 series). Since 2009, the tournament has been a part of the ATP World 250 series.