How to add attributes to an external link in sitemap in Concrete CMS 5.7
To add some attributes to an external link, like exclude from Nav you need to do the following.
Step 1: Within the dashboard select Sitemap, this will then show the sub menus. Select Page Search.
Step 2 Select your External link and choose attributes from the menu. You will then see the same attribute menu as a Page. Save changes and you are done!