How to preserve a “target” attribute on links in overlays?
In general, all links can be excluded from being processed by the Overlay module. Just add a CSS class named overlay-exclude to the class attribute of the link.

That has also solved my target attribute issue:


 I agree to the site’s &lt;a class="overlay-exclude" href="../../node/5" target="_blank"&gt;Terms of Use&lt;/a&gt;.