You can use hidden pages for content that is not strictly confidential, but isn’t ready for prime time. Hidden pages are excluded from your site’s navigation, so people can only access hidden pages if they know the exact URL. A page is hidden until you add it to a group, tab, or other navigation element in your docs.json.
Some navigation elements like sidebars, dropdowns, and tabs may shift or appear empty on hidden pages.
If you want hidden pages to be indexed for SEO purposes and for their contents to appear when people search within your docs, add the following setting to your docs.json: 
"seo" {
    "indexing": all
}
If you want to exclude a specific hidden page’s content from search engine and internal search results, add noindex: true to the frontmatter of the page. If you have pages that you want only specific groups of your own users to have access to, you can use the selective groups access available through Personalization. If you have pages that you want to maintain strict access control to, you can use Authentication.