should be referenced once using \c \\subpage. `mainpage.md` is the root of the
hierarchy.
-If you need to exclude a page from the public API docs, you need to add it to
-an exclude list in `Doxyfile-user.cmakein`, and ensure that there are no
-references to the page from public API documentation. \c \\if `libapi` can be
-used to add references in content that is otherwise public.
+There are two subdirectories, `user/` and `lib/`, determining the highest
+documentation level where the page appears. If you add pages to `lib/`, ensure
+that there are no references to the page from public API documentation.
+\c \\if `libapi` can be used to add references in content that is otherwise
+public.
Generally, the pages should be on a high enough level and provide overview
content that is useful enough such that it is not necessary to exclude them
from the library API documentation.