, ▁emphas izing ▁the ▁un ambigu ous ▁identity ▁of ▁data ▁objects ▁and ▁the ▁separation ▁between ▁data ▁storage , ▁data ▁character ization , ▁and ▁schema ▁development . ▁ ▁The ▁use ▁of ▁non - sem antic ▁U UID s ▁combined ▁with ▁a ▁simple ▁attribute - value ▁model ▁draw s ▁a ▁clear ▁distinction ▁between ▁identity ▁and ▁data . ▁ ▁Although ▁u - forms ▁share ▁certain ▁design ▁characteristics ▁with ▁serial ization ▁formats ▁such ▁as ▁XML , ▁they ▁should ▁not ▁be ▁confused ▁with ▁such ▁represent ational ▁formats . ▁ ▁Since ▁u - forms ▁are ▁abstract , ▁they ▁do ▁not ▁specify ▁any ▁particular ▁represent ational ▁format . ▁Indeed , ▁they ▁may ▁be ▁stored ▁as ▁or ▁communic ated ▁via ▁XML ▁or ▁other ▁types ▁of ▁serial ization . ▁ ▁Oper ations ▁▁ ▁The ▁operations ▁defined ▁for ▁a ▁u - form ▁are ▁similar ▁to ▁associ ative ▁arrays : ▁▁ ▁Set _ Attribute : ▁Bind ▁an ▁attribute ▁name ▁to ▁a ▁value ▁( rep la cing ▁any ▁existing ▁binding ▁to ▁that ▁name ) ▁ ▁Delete _ Attribute : ▁Un bind ▁an ▁attribute ▁name ▁from ▁a ▁value ▁and ▁remove ▁the ▁name ▁from ▁the ▁u - form ▁ ▁Get _ Attribute : ▁Find ▁the ▁value ▁( if ▁any ) ▁that ▁is ▁bound ▁to ▁a ▁name . ▁ ▁List _ Attributes : ▁Find ▁all ▁names ▁that ▁have ▁a ▁non - empty ▁value . ▁ ▁Properties ▁▁ ▁U - forms ▁have ▁the ▁following ▁properties : ▁▁ ▁A ▁U UID ▁is ▁defined ▁as ▁an ▁array ▁of ▁bytes ▁that ▁is ▁intended ▁to ▁be ▁unique ▁in ▁the ▁Un iverse . ▁Note