Creating Custom Taxonomy for Portfolio CPT of Toranj WP Theme

functions.php

/*------------------------------------------------------------*/
/*	Register Custom Portfolio Taxonomy	*/
/*------------------------------------------------------------*/
if ( ! function_exists( 'my_custom_portfolio_taxonomy' ) ) :

function my_custom_portfolio_taxonomy() {

	$labels = array(
		'name'                       => _x( 'Portfolio Categories', 'Taxonomy General Name', 'owlabpfl' ),
		'singular_name'              => _x( 'Portfolio Category', 'Taxonomy Singular Name', 'owlabpfl' ),
		'menu_name'                  => __( 'Portfolio Categories', 'owlabpfl' ),
		'all_items'                  => __( 'All Portfolio Categories', 'owlabpfl' ),
		'parent_item'                => __( 'Parent Portfolio Category', 'owlabpfl' ),
		'parent_item_colon'          => __( 'Parent Portfolio Category:', 'owlabpfl' ),
		'new_item_name'              => __( 'New Portfolio Category Name', 'owlabpfl' ),
		'add_new_item'               => __( 'Add New Portfolio Category', 'owlabpfl' ),
		'edit_item'                  => __( 'Edit Portfolio Category', 'owlabpfl' ),
		'update_item'                => __( 'Update Portfolio Category', 'owlabpfl' ),
		'separate_items_with_commas' => __( 'Separate portfolio categories with commas', 'owlabpfl' ),
		'search_items'               => __( 'Search portfolio categories', 'owlabpfl' ),
		'add_or_remove_items'        => __( 'Add or remove portfolio categories', 'owlabpfl' ),
		'choose_from_most_used'      => __( 'Choose from the most used portfolio categories', 'owlabpfl' ),
		'not_found'                  => __( 'Not Found', 'owlabpfl' ),
	);
	$args = array(
		'labels'                     => $labels,
		'hierarchical'               => true,
		'public'                     => true,
		'show_ui'                    => true,
		'show_admin_column'          => true,
		'show_in_nav_menus'          => false,
		'show_tagcloud'              => true,
	);
	register_taxonomy( '_portfolio_category', array( 'owlabpfl' ), $args );

}

// Hook into the 'init' action
add_action( 'init', 'my_custom_portfolio_taxonomy', 0 );

endif;