docs: public String toIPTC(SubjectReferenceSystem srs) {
  		StringBuffer b = new StringBuffer();
  		b.append("IPTC:");
  		b.append(getNumber());
  		b.append(":");
  		if (getNumber().endsWith("000000")) {
  			b.append(toIPTCHelper(srs.getName(this)));
  			b.append("::");
  		} else if (getNumber().endsWith("000")) {
  			b.append(toIPTCHelper(srs.getName(srs.get(getNumber().substring(0, 2) + "000000"))));
  			b.append(":");
  			b.append(toIPTCHelper(srs.getName(this)));
  			b.append(":");
  		} else {
  			b.append(toIPTCHelper(srs.getName(srs.get(getNumber().substring(0, 2) + "000000"))));
  			b.append(":");
  			b.append(toIPTCHelper(srs.getName(srs.get(getNumber().substring(0, 5) + "000"))));
  			b.append(":");
  			b.append(toIPTCHelper(srs.getName(this)));
  		}
  		return b.toString();
  	}