jQuery Plugin Lab

What's wrong with this plugin?

by ramyaaviji

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
 */
;(function($, document, window, undefined) {
    $.fn.externalize = function() {
        
        if(this.attr('rel') == 'external') {
         
            this
                .attr('target', '_blank')
                .append('\u2B00');
            
        }
        return this;
    };
 
})(jQuery, document, window);

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