code: public void setCheckIdIdref(boolean checkIdIdref) {
      properties.put(RngProperty.CHECK_ID_IDREF, checkIdIdref ? Flag.PRESENT : null);
    }
docs: Specifies whether to perform checking of ID/IDREF/IDREFS attributes in accordance with
  RELAX NG DTD Compatibility.
  
  @param checkIdIdref <code>true</code> if ID/IDREF/IDREFS checking should be performed;
  <code>false</code> otherwise
  
  @see #getCheckIdIdref
  @see <a href="http://www.oasis-open.org/committees/relax-ng/compatibility.html#id">RELAX NG DTD Compatibility</a>