This blog platform is powered by Quam Plures.
You are currently looking at an info page about this system. It is cross-posted among the demo blogs. Thus, this page will be linked on each of these blogs.
Cross-posting across multiple blogs is an advanced feature that is not on by default. The primary category is attached to blog #1, so clicking this link from any blog will display this item in blog #1.
Info pages use post type "Page" and are very much like regular posts, except that they do not appear in the regular flow of posts. You place them in a container using the "Simple Page list" widget.
If needed, a template can format info pages differently from regular posts. For example in a default installation, this template does not have a sidebar on "pages", or offer any feedback options.