Includes and Navigation
Include files are small, simple files that get pulled in to deliver the same content on multiple pages. For example, headers and footers are often include files, because the same content is used on every website page. This way, to make a change, only one modification needs to be made to the include file, rather than making the change to every unique page.
Unlike other reusable content, which can be placed in editable regions, include files are hardcoded into the design of the page. It is possible to configure page properties for a page so that the include file being called can be changed on a page-by-page basis, but the location of the include stays the same.
Some include files are either simple text or source code files, with an extension of .inc, but includes with more extensive styling commonly exist as .pcf page files. Include files are generally found at the site root within the folder
One of the most common uses for include files is side navigation, or the links on a page that point to other pages in that section.
The navigation include is usually named _sidenav.inc. Each section has its own sidenav, and each page in the section pulls in the same sidenav file for that section. If a page in the section is changed, only the include file needs to be edited to reflect that. The change then automatically appears on all other pages in the section.
Some sidenavs are nested, meaning they show links to pages in folders either above or below the current section. However, there is still only one sidenav per folder, and each sidenav only lists pages in that folder. If you have questions about how your specific sidenav functions, contact an administrator at your institution.
Most sidenavs are a plain list of links, corresponding to the pages in the section. Edit the file like you would a regular page, inserting a link to add it to the sidenav, deleting a link, or modifying the text or path.
When creating a new page, there is an option to create a new navigation item along with the page, which automatically adds the appropriate link to the include file. However, any subsequent changes to pages, such as moving them, renaming them, or deleting them, requires you to manually update the sidenav as well.