Each page in Hugo **has to define** front matter. On top of [Hugo's front matter](https://gohugo.io/content-management/front-matter/#fields), you can use the following settings unique to the theme.
A front matter is marked with {{% badge style="green" icon="fa-fw fab fa-markdown" title=" " %}}Front Matter{{% /badge %}} badge throughout the documentation.
The values reflect example options. The defaults can be taken from the [annotated example](#annotated-frontmatter-options) below or the individual documentation.
You can change how the theme expands menu entries on the side of the content with the `alwaysopen` setting on a per page basis. If `alwaysopen=false` for any given entry, its children will not be shown in the menu as long as it is not necessary for the sake of navigation.
The theme generates the menu based on the following rules:
- all parent entries of the active page including their siblings are shown regardless of any settings
- immediate children entries of the active page are shown regardless of any settings
- if not overridden, all other first level entries behave like they would have been given `alwaysopen=false`
- if not overridden, all other entries of levels besides the first behave like they would have been given `alwaysopen=true`
- all visible entries show their immediate children entries if `alwaysopen=true`; this proceeds recursively
- all remaining entries are not shown
You can see this feature in action on the example page for [children shortcode](shortcodes/children) and its children pages.
To stay with the initial example: Suppose you want `level-one` appear in the sidebar but don't want to generate a page for it. So the entry in the sidebar should not be clickable but should show an expander.
For this, open `content/level-one/_index.md` and add the following frontmatter