It's a secret...
To create a new secret page, enter in your URL bar a pagename with the format
secret:[anything]
and then navigate to “Page > Create this page”
For example:
https://arcanapoli.com/doku.php?id=secret:debdiary
Only logged-in users with the Editor role will be able to see Secret pages. When you've created a new Secret page, add it to this list… or don't….