Have you ever had a news section or a blog linked in your main navigation, but really didn't want a giant drop down list of EVERY blog of news article in existence showing up underneath?
The good news is Concrete CMS has a page attribute you can create that will make it so that these page entries do not appear in Autonav blocks. It is called "Exclude Subpages Pages from Navigation".
You can set up the attribute by:
1.) Going to the Page Attributes pages in you dashboard (/dashboard/pages/attributes).
2.) Creating a new page attribute of type "Checkbox".
3.) Name it "Exclude Subpages from Navigation".
4.) Make sure the handle is exclude_subpages_from_nav - IMPORANT the handle must be exactly this, or it won't work.
5.) Leave everything default and save the new Page Attribute.
6.) Go to the page you want to exclude subpages under (like your blog or news page) and apply the attribute. Make sure it's checked, and then save it. Don't forget to publish the version!
7.) Voila! The sub pages will not appear in your navigation.