: S ites ▁of ▁Special ▁Scient ific ▁Interest ▁in ▁Scotland ▁Category : Special ▁Prote ction ▁Are as ▁in ▁Scotland <0x0A> </s> ▁NAT O ▁J oint ▁Military ▁Sym b ology ▁is ▁the ▁NAT O ▁standard ▁for ▁military ▁map ▁mark ing ▁symbols . ▁Origin ally ▁published ▁in ▁ 1 9 8 6 ▁as ▁Al lied ▁Pro ced ural ▁Public ation ▁ 6 ▁( APP - 6 ), ▁NAT O ▁Military ▁Symbol s ▁for ▁Land ▁Based ▁Systems , ▁the ▁standard ▁has ▁evol ved ▁over ▁the ▁years ▁and ▁is ▁currently ▁in ▁its ▁fourth ▁version ▁( APP - 6 C ). ▁The ▁symbols ▁are ▁designed ▁to ▁enh ance ▁NAT O ' s ▁joint ▁inter oper ability ▁by ▁providing ▁a ▁standard ▁set ▁of ▁common ▁symbols . ▁AP P - 6 ▁constit uted ▁a ▁single ▁system ▁of ▁joint ▁military ▁sym b ology ▁for ▁land , ▁air , ▁space ▁and ▁sea - based ▁form ations ▁and ▁units , ▁which ▁can ▁be ▁displayed ▁for ▁either ▁autom ated ▁map ▁display ▁systems ▁or ▁for ▁manual ▁map ▁mark ing . ▁It ▁covers ▁all ▁of ▁the ▁joint ▁services ▁and ▁can ▁be ▁used ▁by ▁them . ▁ ▁History ▁The ▁first ▁basic ▁military ▁map ▁symbols ▁began ▁to ▁be ▁used ▁by ▁western ▁arm ies ▁in ▁the ▁dec ades ▁following ▁the ▁end ▁of ▁the ▁Napole onic ▁Wars . ▁During ▁World ▁War ▁I , ▁there ▁was ▁a ▁degree ▁of ▁harm on isation ▁between ▁the ▁British ▁and ▁French ▁systems , ▁including ▁the ▁ad option ▁of ▁the ▁colour ▁red ▁for ▁enemy ▁forces ▁and ▁blue ▁for ▁al lies ; ▁the ▁British ▁had ▁previously ▁used