New Post: http://www.mysite.com/en-US/sitemap.xml is showing pages where "Menu item" is empty.

I fully understand the reason for the default behavior of including the pages with empty "Menu item" in sitemap.xml.

I don't want some pages to be discovered for some reason on my site. I would like to customize sitemap.xml generation.

Is there a way I can change this behavior, can you give me an idea where to start?

Thanks burningice for taking time to answer my question.