WP Taxonomy

<?php
/************************************************************************************
* Here's an example of registering a "people_cat" taxonomy:
* To register a taxonomy, you use the register_taxonomy() function.
* The "people" taxonomy is defined. It's defined to work for posts.
* A rewrite slug is defined to make the url into '/person/' instead of '/people/'.
*The capabilities line is optional. Without it, WordPress will default capabilities to the same users as posts. As shown above, this will allow any user with the custom "edit_guides" capability to assign the taxonomy to a post and any user with the custom "publish_guides" capability to create new taxonomy items.
*************************************************************************************/
function themename_custom_taxonomy() {
    // create a new taxonomy
    register_taxonomy(
        'portfolio_cat',        // must not contain capital letters or spaces
        'post',         // (post/custom post) type name
        array(
                'hierarchical' => true,
                'label' => 'Portfolio Categories', //Display Name
                'query_var' => true,
                'rewrite' => array('slug' => 'portfolio-category')
            )
    );
}
add_action( 'init', 'themename_custom_taxonomy' );

/************************************************************************************
Usage of Custom Taxonomy
*************************************************************************************/
'portfolio_cat' => 'Feature';   //
?>