add_action('init', 'campaign_register');

function campaign_register() {

    $labels = array(
        'name' => _x('My Campaigns', 'post type general name'),
        'singular_name' => _x('Campaign Item', 'post type singular name'),
        'add_new' => _x('Add New', 'campaign item'),
        'add_new_item' => __('Add New Campaign Item'),
        'edit_item' => __('Edit Campaign Item'),
        'new_item' => __('New Campaign Item'),
        'view_item' => __('View Campaign Item'),
        'search_items' => __('Search Campaigns'),
        'not_found' =>  __('Nothing found'),
        'not_found_in_trash' => __('Nothing found in Trash'),
        'parent_item_colon' => ''
    );

    $args = array(
        'labels' => $labels,
        'public' => true,
        'publicly_queryable' => true,
        'show_ui' => true,
        'query_var' => true,
        'menu_icon' => get_stylesheet_directory_uri() . '/images/icon.gif',
        'rewrite' => true,
        'capability_type' => 'page',
        'hierarchical' => false,
        'menu_position' => null,
        'supports' => array('title','editor','thumbnail')
      );

    register_post_type( 'campaign' , $args );
}

add_action( 'init', 'create_product_taxonomies', 0 );

function create_product_taxonomies() {

  register_taxonomy('Product_Categories',array('campaign'), array(
    'hierarchical' => true,
    'public' => true,
    'label' => 'Product Categories',
    'singular_label' => 'Product Category',
    'show_ui' => true,
    'query_var' => true,
    'capabilities' => array ('manage_terms'),
    'rewrite' => array( 'slug' => 'product' ),
  ));

}