URLMeta.org only extracts the data in head section of a page. Title, Description, Image, Logo and Feed. It looks for RSS, ATOM and oEmbed feed. All of these these information are only extracted and provided if present in the page.
If no protocol is found then it will fallback to title tag and description attribute of meta tag.
Yes, you can. Simply add <meta name="urlmeta" content="no"> in head section of your website/page.
If you want a more general way then pass a custom header urlmeta with no as its value.
Here are some examples on how to set it up on your server: