Displaying only specific pages in the nav bar

I’ve been using this

<?php wp_list_pages(‘title_li=’); ?>

to list my pages in the nav bar, now I want to add pages without having them show up in the nav bar. For example, I would have a services page and on that page a brief description of all of the available services and links that would take them to corresponding pages. How do I display only specific pages in the nav bar?