▁chemical , ▁bi ological , ▁radi ological ▁or ▁nuclear ▁events ▁two ▁colour ▁representation : ▁ ▁Blue , ▁Green , ▁or ▁black ▁for ▁friendly ▁icons ▁Red ▁for ▁enemy ▁icons ▁One ▁colour ▁representation : ▁Single ▁line ▁border ▁for ▁friendly ▁icons ▁double ▁line ▁border ▁for ▁enemy ▁icons , ▁and ▁un border ed ▁icons ▁were ▁l abeled ▁with ▁" EN " ▁to ▁the ▁lower ▁right ▁corner ▁ ▁Battle ▁dimension ▁Battle ▁dimension ▁defines ▁the ▁primary ▁mission ▁area ▁for ▁the ▁oper ational ▁object ▁within ▁the ▁batt les pace . ▁An ▁object ▁can ▁have ▁a ▁mission ▁area ▁above ▁the ▁Earth ' s ▁surface ▁( i . e ., ▁in ▁the ▁air ▁or ▁outer ▁space ), ▁on ▁it , ▁or ▁below ▁it . ▁If ▁the ▁mission ▁area ▁of ▁an ▁object ▁is ▁on ▁the ▁surface , ▁it ▁can ▁be ▁either ▁on ▁land ▁or ▁sea . ▁The ▁sub sur face ▁dimension ▁concerns ▁those ▁objects ▁whose ▁mission ▁area ▁is ▁below ▁the ▁sea ▁surface ▁( e . g ., ▁sub mar ines ▁and ▁sea ▁mines ). ▁Some ▁cases ▁require ▁adj ud ic ation ; ▁for ▁example , ▁an ▁Army ▁or ▁Marine ▁hel ic opter ▁unit ▁is ▁a ▁man oe uv ring ▁unit ▁( i . e ., ▁a ▁unit ▁whose ▁ground ▁support ▁assets ▁are ▁included ) ▁and ▁is ▁thus ▁represented ▁in ▁the ▁land ▁dimension . ▁Like wise , ▁a ▁landing ▁craft ▁whose ▁primary ▁mission ▁is ▁fer ry ing ▁personnel ▁or ▁equipment ▁to ▁and ▁from ▁shore ▁is ▁a ▁mar itime ▁unit ▁and ▁is ▁represented ▁in ▁the ▁sea ▁surface ▁dimension . ▁A ▁landing ▁craft ▁whose ▁primary ▁mission