jQuery Plugin Lab

What's wrong with this plugin?

by busyfmlyman

HTML

<a href="http://www.google.com" rel="external">Google</a>

<a href="http://www.yahoo.com" rel="external">Yahoo</a>

<a href="http://www.bing.com" rel="external">Bing</a>

<a href="#" class="local">Local</a>

JavaScript

/**
 * Externalize Plugin
 * 
 * configures links that relate to external sites open in a new tab,
 * colors them red and appends an arrow to indicate that it is external
 */
$.fn.externalize = function () {

    return this.each(function () {
        var $this = $(this);
        if ($this.attr('rel') == 'external') {

            $this.attr('target', '_blank')
                .append('\u2197');

        });

    });
};

$("a")
    .externalize()
    .filter('.local')
    .css('font-weight', 'bold');