docs: function write_BIFF2LABEL(r/*:number*/, c/*:number*/, val) {
  	var out = new_buf(8 + 2*val.length);
  	write_BIFF2Cell(out, r, c);
  	out.write_shift(1, val.length);
  	out.write_shift(val.length, val, 'sbcs');
  	return out.l < out.length ? out.slice(0, out.l) : out;
  }