@@ 5439,7 5439,9 @@ facility is implemented in the @code{(gnu packages)} module.
@cindex customization, of packages
@cindex package module search path
Users can store package definitions in modules with different
-names---e.g., @code{(my-packages emacs)}. These package definitions
+names---e.g., @code{(my-packages emacs)}@footnote{Note that the file
+name and module name must match. @xref{Modules and the File System,,,
+guile, GNU Guile Reference Manual}, for details.} These package definitions
will not be visible by default. Thus, users can invoke commands such as
@command{guix package} and @command{guix build} have to be used with the
@code{-e} option so that they know where to find the package, or use the