[thelist] Target="_blank" error

[Stacie Pearson]

How come I am getting this error when I validate my markup?

The tag: "a" doesn't have an attribute: "target" in currently active
versions.[XHTML 1.0 strict]

The error is referring to: target="_blank".
I thought that is what I was supposed to use if I wanted the browser to open
a new tab/window, and not be taken from my site.

Below is the code:

<p>Portfolio photography by <a href="http://www.paulpearsonphoto.com/"
title="See Paul's site" target="_blank">Paul Pearson Photography</a></p>

Thanks,
Stacie