▁way ▁to ▁add ▁a ▁metadata ▁to ▁any ▁XML - based ▁language . ▁Indeed , ▁one ▁of ▁the ▁earliest ▁documents ▁bearing ▁the ▁R DF / A ▁Syntax ▁name ▁has ▁the ▁sub - title ▁A ▁collection ▁of ▁attributes ▁for ▁layer ing ▁R DF ▁on ▁XML ▁languages . ▁The ▁document ▁was ▁written ▁by ▁Mark ▁Bir beck ▁and ▁Steven ▁P ember ton , ▁and ▁was ▁made ▁available ▁for ▁discussion ▁on ▁October ▁ 1 1 , ▁ 2 0 0 4 . ▁ ▁In ▁April ▁ 2 0 0 7 ▁the ▁X HTML ▁ 2 ▁Working ▁Group ▁produced ▁a ▁module ▁to ▁support ▁R DF ▁annotation ▁within ▁the ▁X HTML ▁ 1 ▁family . ▁ ▁As ▁an ▁example , ▁it ▁included ▁an ▁extended ▁version ▁of ▁X HTML ▁ 1 . 1 ▁dub bed ▁X HTML + R DF a ▁ 1 . 0 . ▁Although ▁described ▁as ▁not ▁representing ▁an ▁intended ▁direction ▁in ▁terms ▁of ▁a ▁formal ▁markup ▁language ▁from ▁the ▁W 3 C , ▁limited ▁use ▁of ▁the ▁X HTML + R DF a ▁ 1 . 0 ▁D TD ▁did ▁subsequently ▁appear ▁on ▁the ▁public ▁Web . ▁ ▁October ▁ 2 0 0 7 ▁saw ▁the ▁first ▁public ▁Working ▁D raft ▁of ▁a ▁document ▁entitled ▁R DF a ▁in ▁X HTML : ▁Syntax ▁and ▁Process ing . ▁ ▁This ▁su pers eded ▁and ▁expanded ▁upon ▁the ▁April ▁draft ; ▁it ▁contained ▁rules ▁for ▁creating ▁an ▁R DF a ▁parser , ▁as ▁well ▁as ▁gu idel ines ▁for ▁organizations ▁wish ing ▁to ▁make ▁practical ▁use ▁of ▁the ▁technology