WordPress Custom Post Type Register Function

functions.php

add_action('init', 'create_units_post_type');

function create_units_post_type() {

	$labels = array(
		'name' => __('Site Plan'),
		'singular_name' => __('Unit'),
		'all_items' => __('All Units'),
		'add_new' => _x('Add new Unit', 'Unit'),
		'add_new_item' => __('Add new Unit'),
		'edit_item' => __('Edit Unit'),
		'new_item' => __('New Unit'),
		'view_item' => __('View Unit'),
		'search_items' => __('Search in Unit'),
		'not_found' =>  __('No Unit found'),
		'not_found_in_trash' => __('No Units found in trash'),
		'parent_item_colon' => ''
	);
	$args = array (
		'labels' => $labels,
		'public' => true,
		'has_archive' => true,
		'menu_icon' => 'dashicons-admin-multisite',
		'rewrite' => array('slug' => 'units'),
		'taxonomies' => array( /*'category',*/ 'unit'),
		'query_var' => true,
		'menu_position' => 22,
		'supports'=> array('thumbnail' , /*'custom-fields',*/ 'title', 'editor', 'excerpt')
	);
	register_post_type('units', $args);
}