WooCommerce Germanized: Add String before Item / Product Title in PDF

functions.php

<?php

// add this snippet to your functions.php if you want this kind of funcitonality

function add_something_before_invoice_item_name($name, $item) {
    // getting category terms
    $terms = get_the_terms($item->get_product_id(), 'product_cat');

    // if this product has the category "Premium", it will be prepended to the name
    foreach ($terms as $term)
        if ($term->name === 'Premium')
            return 'Premium: ' . $name;

    // otherwise the name will be passed down unedited
    return $name;
}

// adding the filter
add_filter( 'woocommerce_gzdp_invoice_item_name', 'add_something_before_invoice_item_name', 10, 99 );