This tab has a simple field in which you can enter a keyword and the list is filtered by this keyword. Simple as the sun, using easy JS. Especially useful when there are a lot of categories, like in case of a shop. It needs jQuery to run ! Now you can find this plugin on my site: http://www.gadratilprogramming.net/shop/wordpress-plugins/wp-admin-category-search/ Also, the PRO version is out, featuring autocomplete functionality: http://www.gadratilprogramming.net/shop/wordpress-plugins/wp-admin-category-search-pro/