Reference for “xml:id Requirements”

@TechReport{Marsh:03:R,
  author      = "Jonathan Marsh",
  title       = "xml:id Requirements",
  month       = aug,
  note        = "http://www.w3.org/TR/2003/WD-xml-id-req-20030806",
  year        = "2003",
  bibsource   = "http://w2.syronex.com/jmr/w3c-biblio",
  type        = "{W3C} Working Draft",
  institution = "W3C",
}