Magento Create Category Attribute

magento_create_category_attribute.php

// ## Note: If not in a module sql setup use the following 2 lines
require_once('app/Mage.php');
Mage::app()->setCurrentStore(Mage::getModel('core/store')->load(Mage_Core_Model_App::ADMIN_STORE_ID));
// ## Note: Setup the new category attribute
$installer = new Mage_Sales_Model_Mysql4_Setup;
$installer->startSetup();
$installer->addAttribute('catalog_category', 'additional_css', array(
                        'type'              => 'text',
                        'backend'           => '',
                        'frontend'          => '',
                        'label'             => 'Custom CSS',
                        'input'             => 'textarea',
                        'class'             => '',
                        'source'            => '',
                        'global'            => false,
                        'visible'           => true,
                        'required'          => false,
                        'user_defined'      => false,
                        'default'           => '',
                        'searchable'        => false,
                        'filterable'        => true,
                        'comparable'        => false,
                        'visible_on_front'  => false,
                        'unique'            => false,
                        'wysiwyg'           => true,
                        'position'          => 0,
                        'group'             => 'Display Settings',
                    ));
$installer->endSetup();