ten-forty or 10/40 Window Not a new computer program for doing your taxes, but rather a geographic region extending from the 10th to 40th parallel that encompasses most of North Africa, parts of the Middle East, Korea and Japan. This window represents the largest unreached part of the world.

i found this definition of the 10/40 window at the urbana.org website. do you know what a 10/40 window is?