▁spec ifies ▁the ▁dat atype ▁of ▁text ▁specified ▁for ▁use ▁with ▁the ▁property ▁attribute ▁ ▁typeof ▁– ▁optional ▁attribute ▁that ▁spec ifies ▁the ▁R DF ▁type ( s ) ▁of ▁the ▁subject ▁or ▁the ▁partner ▁resource ▁( the ▁resource ▁that ▁the ▁metadata ▁is ▁about ). ▁ ▁Ben ef its ▁There ▁are ▁five ▁" pr inci ples ▁of ▁inter oper able ▁metadata " ▁met ▁by ▁R DF a . ▁ ▁Publish er ▁Independ ence ▁– ▁each ▁site ▁can ▁use ▁its ▁own ▁standards ▁ ▁Data ▁Re use ▁– ▁data ▁are ▁not ▁dup licated . ▁Se par ate ▁XML ▁and ▁HTML ▁sections ▁are ▁not ▁required ▁for ▁the ▁same ▁content . ▁ ▁Self ▁Cont ain ment ▁– ▁the ▁HTML ▁and ▁the ▁R DF ▁are ▁separated ▁ ▁Sch ema ▁Mod ular ity ▁– ▁the ▁attributes ▁are ▁re usable ▁ ▁Additionally ▁R DF a ▁may ▁benefit ▁web ▁access ibility ▁as ▁more ▁information ▁is ▁available ▁to ▁assist ive ▁technology . ▁ ▁Us age ▁ ▁There ▁is ▁a ▁growing ▁number ▁of ▁tools ▁for ▁better ▁usage ▁of ▁R DF a ▁voc ab ular ies ▁and ▁R DF a ▁annotation . ▁ ▁HTML + R DF a ▁statistics ▁▁ ▁The ▁simplified ▁approaches ▁to ▁sem ant ically ▁annot ate ▁information ▁items ▁in ▁web pages ▁were ▁greatly ▁encourag ed ▁by ▁the ▁HTML + R DF a ▁ ▁( re leased ▁in ▁ 2 0 0 8 ) ▁and ▁Micro form ats ▁( since ▁~ 2 0 0 5 ) ▁standards . ▁▁ ▁these ▁standards ▁were ▁encoding ▁events , ▁contact ▁information , ▁products , ▁and ▁so