diff --git a/lisp/files.el b/lisp/files.el
index 462abaf2dc7..f9341ab5a90 100644
--- a/lisp/files.el
+++ b/lisp/files.el
@@ -722,12 +722,14 @@ code contained within those files and directories without an explicit
 request by the user.
 One important case when this might happen is when `flymake-mode' is
 enabled (for example, when it is added to a mode hook).
-Each element of the list should be a string:
+
+Each element of the list should be a string naming a file or a directory
+by their abbreviated file names:
 - If it ends in \"/\", it is considered as a directory name and means that
   Emacs should trust all the files whose name has this directory as a prefix.
 - Otherwise, it is considered a file name.
-Use abbreviated file names.  For example, an entry \"~/mycode/\" means
-that Emacs will trust all the files in your directory \"mycode\".
+For example, an entry \"~/mycode/\" means that Emacs will trust all the
+files in the directory \"mycode\" under your home directory.
 This variable can also be set to `:all', in which case Emacs will trust
 all files, which opens a gaping security hole.  Emacs Lisp authors
 should note that this value must never be set by a major or minor mode."