code: Rule IfieldDiscography() {
  		return Sequence(String("[D:"),
  				ZeroOrMore(WSP()).suppressNode(),
  				TexTextIfield(),
  				String("]"))
  			.label(IfieldDiscography);
  	}
docs: ifield-discography ::= %5B.%44.%3A *WSP tex-text-ifield %5D<p>
  <tt>[D:..]</tt>