+
+## internal pages
+
+This plugin creates a page for each aggregated item.
+
+Currently, by default, these pages have the ".html" extension, and are
+first-class wiki pages -- which allows them to be inlined into blogs
+and even edited.
+
+That turns out to not be ideal for aggregated content, because publishing
+files for each of those pages is a waste of disk space and CPU, and you probably
+don't want to allow them to be edited. So, there is an alternate method
+that can be used, turned on by the `aggregateinternal` option in the setup
+file.
+
+If `aggregateinternal` is enabled, aggregated pages are stored in the source
+directory with a "._aggregate" extension. These pages cannot be edited by
+web users, and do not generate first-class wiki pages. They can only be
+inlined into a blog.
+
+If you are already using aggregate and want to enable `aggregateinternal`,
+you should follow this process:
+
+1. Update all [[PageSpecs|ikiwiki/PageSpec]] that refer to the aggregated
+ pages -- such as those in inlines. Put "internal()" around globs
+ in those PageSpecs. For example, if the PageSpec was "foo/*", it should
+ be changed to "internal(foo/*)". This has to be done because internal
+ pages are not matched by regular globs.
+2. Use [[ikiwiki-transition]] to move all existing aggregated `.html`
+ files. The command to run is `ikiwiki-transition aggregateinternal $srcdir`
+3. Turn on `aggregateinternal` in the setup file and rebuild the wiki.