# Using custom attributes in menus and taxonomy archives
Attributes that can be used for the layered nav are a custom taxonomy, which means you can display them in menus, or display products by attributes. This requires some work on your part, and archives must be enabled.
> **Note:** This is a **Developer level** doc. If you are unfamiliar with code/templates and resolving potential conflicts, select a [WooExpert or Developer](https://woo.com/customizations/) for assistance. We are unable to provide support for customizations under our [Support Policy](https://woo.com/support-policy/).
function wc_reg_for_menus( $register, $name = '' ) {
if ( $name == 'pa_size' ) $register = true;
return $register;
}
```
Custom attribute slugs are prefixed with `pa_`, so an attribute called `size` would be `pa_size`
Now use your attribute in **Appearance > Menus**. You will notice, however, that it has default blog styling when you click on a link to your taxonomy term.
# Create a template
You need to theme your attribute to make it display products as you want. To do this:
1. Copy `woocommerce/templates/taxonomy-product_cat.php` into your theme folder
2. Rename the template to reflect your attribute – in our example we’d use `taxonomy-pa_size.php`
You should now see this template when viewing taxonomy terms for your custom attribute.