▁images ; ▁metadata , ▁such ▁as ▁descript ors ▁and ▁ident ifiers ; ▁and ▁structure ▁for ▁describing ▁the ▁relationships ▁between ▁the ▁resources . ▁ ▁It ▁is ▁becoming ▁difficult ▁for ▁users ▁of ▁content ▁to ▁identify ▁and ▁interpret ▁the ▁different ▁intellectual ▁property ▁rights ▁that ▁are ▁associated ▁with ▁the ▁elements ▁of ▁multimedia ▁content . ▁For ▁this ▁reason , ▁new ▁solutions ▁are ▁required ▁for ▁the ▁access , ▁delivery , ▁management ▁and ▁protection ▁of ▁this ▁content . ▁ ▁Digital ▁Item ▁Dec laration ▁ ▁M PE G - 2 1 ▁propos es ▁to ▁facil itate ▁a ▁wide ▁range ▁of ▁actions ▁involving ▁Digital ▁Items ▁so ▁there ▁is ▁a ▁need ▁for ▁a ▁very ▁precise ▁description ▁for ▁defining ▁exactly ▁what ▁constit utes ▁such ▁an ▁item . ▁▁ ▁A ▁Digital ▁Item ▁Dec laration ▁( D ID ) ▁is ▁a ▁document ▁that ▁spec ifies ▁the ▁make up , ▁structure ▁and ▁organisation ▁of ▁a ▁Digital ▁Item . ▁The ▁purpose ▁of ▁the ▁Digital ▁Item ▁Dec laration ▁is ▁to ▁describe ▁a ▁set ▁of ▁abstract ▁terms ▁and ▁concepts , ▁to ▁form ▁a ▁useful ▁model ▁for ▁defining ▁what ▁a ▁Digital ▁Item ▁is . ▁Following ▁this ▁model , ▁a ▁Digital ▁Item ▁is ▁the ▁digital ▁representation ▁of ▁an ▁object , ▁which ▁is ▁managed , ▁described ▁or ▁ex changed ▁within ▁the ▁model . ▁ ▁Digital ▁Item ▁Ident ification ▁ ▁Digital ▁Item ▁Ident ification ▁( D II ) ▁specification ▁includes ▁not ▁only ▁how ▁to ▁identify ▁Digital ▁Items ▁uniqu ely ▁but ▁also ▁to ▁distinguish ▁different ▁types ▁of ▁them . ▁These ▁Ident ifiers ▁are ▁placed ▁in ▁a ▁specific ▁part ▁of ▁the ▁Digital ▁Item ▁Dec laration ,