code: public void toRSL(StringBuffer buf, boolean explicitConcat) {
  	buf.append("$(");
  	buf.append( value );
  
  	if (defValue != null) {
  	    buf.append(" ");
  	    defValue.toRSL(buf, explicitConcat);
  	}
  
  	buf.append(")");
  
  	if (concatValue == null) return;
  
  	if (explicitConcat) buf.append(" # ");
  
  	concatValue.toRSL(buf, explicitConcat);
      }
docs: Produces a RSL representation of this variable reference.
  
  @param buf buffer to add the RSL representation to.
  @param explicitConcat if true explicit concatination will
  be used in RSL strings.