An 'undefined' page is any page that has been linked to from within Confluence, but that does not yet exist.

Undefined Page Linked From
Our Research Test Page: Our Research Test (Utility)
Sample Blog Post 1 Blog: Sample Blog Post 1 (EdGE)
Sample Blog Post 2 Blog: Sample Blog Post 2 (EdGE)
Section Title Options Page: Section Title Options (Utility)
Site Banner Content Page: Site Banner Content (Utility)