But the one I tried--Wing Commander IV--jolted me out of my seat it was so realistic.

CNN: Build the PC of your dreams... for only about $10,000

It was in one of these forts I first heard Led Zeppelin IV - forever known as ZOSO.

FORBES: Celebration Day: Invoking The Legacy Of Led Zeppelin

The Uptime Institute pioneered a widely adopted metric, with rankings from Tier I through Tier IV that quantify the reliability of megawatt-class power systems.

FORBES: New York, Black Swans, Blackouts and Anti-Fragile Grids

Pursuant to section 302(a) of Public Law 112-208, I hereby determine that chapter 1 of title IV of the 1974 Act (19 U.S.C. 2431-2439) should no longer apply to the Republic of Moldova.

WHITEHOUSE: The White House

If I didn't have a Mark 4 (Canon EOS-1D Mark IV capable of shooting up to 10 frames per second, Ed) or some other really fast camera, I wouldn't have these pictures.

BBC: Tales from the frontline