Ticket #27213: main.php

<?php
/*
        Plugin Name: TGI Tests
        Plugin URI: http://wordpress.org
        Description: Testing
        Author: Marventus
        Version: 1.0
*/

function tgitest_in_category() {
        if( in_category('reviews') )
                echo "This is a test for admins only. Please disregard.";
}
add_action("wp_head", "tgitest_in_category");