some nonfiction works [3]  and doctrinal manuals are available. [4] [5] [6] 7 .French GIGN The  National Gendarmerie Intervention Group , commonly abbreviated  GIGN  ( French :  Groupe d'Intervention de la Gendarmerie Nationale ), is the  French   National Gendarmerie 's  elite   Special Operations   counter-terrorism  and  hostage rescue  unit.