▁different ▁frames ▁are ▁used ▁for ▁the ▁friendly ▁( and ▁assumed ▁friendly ) ▁affili ations ▁in ▁order ▁to ▁distinguish ▁between ▁units ▁and ▁equipment . ▁The ▁SO F ▁( special ▁operations ▁forces ) ▁are ▁assigned ▁their ▁own ▁battle ▁dimension ▁because ▁they ▁typically ▁can ▁operate ▁across ▁several ▁domains ▁( air , ▁ground , ▁sea ▁surface ▁and ▁sub sur face ) ▁in ▁the ▁course ▁of ▁a ▁single ▁mission ; ▁the ▁frames ▁are ▁the ▁same ▁as ▁for ▁the ▁ground ▁( unit ) ▁battle ▁dimension . ▁The ▁other ▁battle ▁dimension , ▁finally , ▁seems ▁to ▁be ▁reserved ▁for ▁future ▁use ▁( there ▁are ▁no ▁instances ▁of ▁its ▁use ▁as ▁of ▁ 2 5 2 5 B ▁Change ▁ 1 ). ▁ ▁Icon ▁pla cement ▁AP P - 6 A ▁defined ▁a ▁standard ▁oct agon ▁boundary ▁within ▁each ▁map ▁symbol ▁frame . ▁This ▁oct agon ▁is ▁not ▁actually ▁shown ▁when ▁symbols ▁are ▁drawn ▁or ▁rendered ▁but , ▁with ▁a ▁few ▁defined ▁exceptions , ▁all ▁icons ▁inside ▁the ▁frame ▁would ▁also ▁fit ▁inside ▁these ▁oct ag ons . ▁AP P - 6 C ▁modified ▁some ▁symbol ▁frames ▁from ▁previous ▁ed itions ▁of ▁the ▁standard . ▁From ▁top ▁to ▁bottom , ▁here ▁is ▁the ▁symbol ▁boundary ▁shown ▁inside ▁the ▁AP P - 6 C ▁frames ▁of ▁space ▁elements , ▁air ▁elements , ▁land ▁units , ▁land ▁equipment ▁and ▁surface ▁sea ▁elements , ▁and ▁sub - sur face ▁sea ▁elements . ▁ ▁Unit ▁icons ▁The ▁icon ▁is ▁the ▁inn erm ost ▁part ▁of ▁a ▁symbol ▁which , ▁when ▁displayed , ▁provides ▁an ▁abstract