Vertical Main Nav With Right Sidebar
If a design requires an isolated section for supporting or related content, using the optional right sidebar will best accommodate this design. This section can be used for links outside of the site that relate to the body content or for help files and tips. Right sidebar can exist in body area only, with vertical main navigation, or horizontal main navigation.
An example scenario would include a multi-page app with many menu items or lengthy text that cannot fit horizontally.
Asides
The HTML <aside> element represents a section of the page with content connected tangentially to the rest, which could be considered separate from that content. These sections are often represented as sidebars or inserts. They often contain the definitions on the sidebars, such as definitions from the glossary; there may also be other types of information, such as related advertisements; the biography of the author; web applications; profile information or related links on the blog.