An intensely hoppy, very strong pale ale without the big maltiness and/or deeper malt flavors of an American barleywine. Strongly hopped, but clean, lacking harshness, and a tribute to historical IPAs. Drinkability is an important characteristic; this should not be a heavy, sipping beer. It should also not have much residual sweetness or a heavy character grain profile.
Bigger than either an English or American IPA in both alcohol strength and overall hop level (bittering and finish). Less malty, lower body, less rich and a greater overall hop intensity than an American Barleywine. Typically not as high in gravity/alcohol as a barleywine, since high alcohol and malt tend to limit drinkability. A showcase for hops.
Russian River Pliny the Elder, Three Floyd's Dreadnaught, Avery Majaraja, Bell's Hop Slam, Stone Ruination IPA, Great Divide Hercules Double IPA, Surly Furious, Rogue I2PA, Moylan's Hopsickle Imperial India Pale Ale, Stoudt's Double IPA, Dogfish Head 90-minute IPA, Victory Hop Wallop
You can view the complete style details on the BJCP website. The 2008 style guide is obsolete but there is a similar 2015 style that you can view below...