▁p ict orial ▁or ▁al phan umeric ▁representation ▁of ▁an ▁oper ational ▁object . ▁The ▁icon ▁port ray s ▁the ▁role ▁or ▁mission ▁performed ▁by ▁the ▁object . ▁AP P - 6 A ▁distingu ishes ▁between ▁icons ▁that ▁must ▁be ▁fr amed ▁or ▁un fr amed ▁and ▁icons ▁where ▁fr aming ▁is ▁optional . ▁ ▁Equ ip ment ▁icons ▁Equ ip ment ▁icons ▁are ▁" frame ▁optional ". ▁ ▁Install ation ▁icons ▁ ▁Mod ifier ▁icons ▁All ▁the ▁previously ▁mentioned ▁symbols ▁can ▁be ▁used ▁independently ▁as ▁well ▁as ▁in ▁combinations . ▁There ▁are ▁also ▁some ▁symbols ▁that ▁cannot ▁appear ▁by ▁themselves , ▁but ▁can ▁only ▁be ▁used ▁to ▁modify ▁other ▁unit ▁symbols : ▁ ▁Common ▁combinations ▁Some ▁of ▁the ▁most ▁common ▁combinations ▁are : ▁ ▁Unit ▁sizes ▁A bove ▁the ▁unit ▁symbol , ▁a ▁symbol ▁representing ▁the ▁size ▁of ▁the ▁unit ▁can ▁be ▁displayed : ▁ ▁The ▁typical ▁commander ▁ranks ▁shown ▁in ▁the ▁table ▁are ▁for ▁illustr ation . ▁Ne ither ▁the ▁actual ▁rank ▁designated ▁for ▁a ▁particular ▁unit ' s ▁commander , ▁nor ▁the ▁rank ▁held ▁by ▁the ▁inc umb ent ▁commander ▁al ters ▁the ▁appropriate ▁symbol . ▁For ▁example , ▁units ▁are ▁period ically ▁commanded ▁by ▁an ▁officer ▁junior ▁to ▁the ▁author ised ▁commander ▁grade , ▁yet ▁a ▁company ▁under ▁the ▁command ▁of ▁a ▁Lieutenant ▁( U . S .) ▁or ▁Captain ▁( Common wealth ) ▁is ▁still ▁indicated ▁with ▁two ▁vertical ▁t icks . ▁Like wise , ▁some ▁peculiar ▁types ▁of ▁companies ▁and ▁det ach ments ▁are ▁author ised ▁a