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

Undefined Page Linked From
Abou Page: About Administrative Permissions (NIOS 8.3)
Configuring ActiveTrust Cloud Clients for Outbound Page: What's New (NIOS 8.3)
Importing and Exporting Data using CSV Import Page: Finding and Restoring Data (NIOS 8.3)
NetMRI Task Pack Page: Viewing Tasks (NIOS 8.3)
Page: Tasks Dashboard (NIOS 8.3)
Page: Provisioning and De-Provisioning Networks (NIOS 8.3)