documenting what private pages are

data/Help.page

@@ -93,7 +93,7 @@ highlighted in yellow, and deletions will be crossed out with a horizontal
 line.  Clicking on the description of changes will take you to the page
 as it existed after those changes.  To revert the page to the revision
 you're currently looking at, just click the "revert" button at the bottom
-of the page, then "Save". 
+of the page, then "Save".
 
 ## Deleting a page
 
@@ -123,3 +123,11 @@ picture into a (markdown-formatted) page as follows: `![fido](fido.jpg)`.
 If you uploaded a PDF `projection.pdf`, you can insert a link to it
 using:  `[projection](projection.pdf)`.
 
+# Private content
+
+By default, wiki content is accessible to all users, whether authenticated
+or not. However, it is possible to define pages or directories as private.
+In this case, you'll need to be authenticated to access them. Only the
+**content** of files will be inaccessible, the name of these files will
+remain visible in "All pages" or in "Recent activity".
+

data/default.conf

@@ -129,12 +129,11 @@ no-edit: Help
 # Leave blank to allow every page to be edited.
 
 private-pages:
-# specifies pages that are considered private, i.e not accessible for
-# anonymous users. This setting overrides any other require-authentication
-# setting, visitors to private pages must be logged in.
-# Full paths and wildcards are both available, meaning that
-# /Dir/Page, /Dir/* and */Page will all blacklist
-# the /Dir/Page page.
+# specifies a comma-separated list of page paths that are considered
+# private, i.e not accessible for anonymous users. This setting overrides
+# any other require-authentication setting, visitors to private pages must
+# be logged in. Full paths and wildcards are both available, meaning that
+# Dir/Page, Dir/* and */Page will all blacklist the Dir/Page page.
 
 default-summary:
 # specifies text to be used in the change description if the author