H6, H06, or H-6 may refer to: Science British NVC community H6, an ecological designation Sanguiin H-6, a dimeric ellagitannin found in Sanguisorba officinalis, the great burnet Hydrogen-6 (H-6 or 6H), an isotope of hydrogen Transportation Aircraft Hughes OH-6 Cayuse, a 1963 American scout helicopter MD Helicopters MH-6 Little Bird, a special forces variant Xian H-6, a Chinese bomber Besson H-6, a French flying boat Sikorsky R-6, a 1943 American helicopter Watercraft HMS H6, a British submarine USS H-6 (SS-149), a United States submarine HMS Hurricane (H06), a British Havant-class destroyer HMS Keith (H06), a British B-class destroyer Other vehicles PRR H6, a steam locomotive Hispano-Suiza H6, an automobile Roads H6 Childs Way, a road in England Highway H06, a road in the Ukraine Other uses <h6></h6>, level 6 heading markup for HTML Web pages, see HTML element#heading Flat-six engine, sometimes marketed as H6 Halloween: The Curse of Michael Myers, the sixth film in the Halloween franchise H6: Diary of a Serial Killer, a movie Composition H6, an explosive H6, a watch possibly made by John Harrison See also 6H (disambiguation)