You can achieve more complex layouts by using nested <frameset> tags. Any frame within a frameset can contain another frameset.
For example, shows a layout of two columns, the first with two rows and the second with three rows. This is created by nesting two <frameset> tags with row specifications within a top-level <frameset> that specifies the columns:
<frameset cols="50%,*">
  <frameset rows="50%,*">
    <frame src="frame1.html">
    <frame src="frame2.html">
  </frameset>
  <frameset rows="33%,33%,*">
    <frame src="frame3.html">
    <frame src="frame4.html">
    <frame src="frame5.html">
  </frameset>
</frameset>
![[Graphic: Figure 4-3]](./figs/wm_0402.gif)