What is "nitrosyl-o-hydroxide"

Nitrosyl-O-hydroxide (molecular formula H O O N) is an isomer of nitrous acid, which has been experimentally observed in the gas phase. HOON contains the longest oxygen-oxygen bond thus far observed in any known molecule, measured to be 1.9149 angstroms. There had been speculation about the existence of this molecule, and ab initio calculations have suggested that it might have a stable chemically bonded structure.