Bug or intentional?

I'm attempting to add a feed post programmatically. The text of the post has a link with a target attribute. The target attribute is getting stripped. I found in the FeedsHelper mdToHtml function, the call to wp_kses includes an array of allowed html tags. The entry for links looks like this:

            'a'          => array(
                'href'    => true,
                'title'   => true,
                'rel'     => true,
                '_target' => true,
            ),

Is the _ before target intentional or a typo/bug in the code? Should target attributes be allowed when creating posts programmatically?

Thanks!