WooCommerce, checkout page: is "Tax" hardcoded?

On the checkout page the total amount is followed by “(includes xxx Tax)”
Screendump

This text is created in woocommerce/includes/wc-cart-functions.php:

$value .= '<small class="includes_tax">' . sprintf( __( '(includes %s)', 'woocommerce' ), implode( ', ', $tax_string_array ) . $estimated_text ) . '</small>';

The “includes” can be fixed using translate, but the “Tax” part is another story! I cannot understand how “Tax” is stored in the $tax_string_array?

Is it hardcoded?

“Tax” is already translated to the local name “Moms” so it’s not that easy ??

You can see the full code here

Thanks in advance