"List of directories to search for Info documentation files.
nil means not yet initialized. In this case, Info uses the environment
variable INFOPATH to initialize it, or `Info-default-directory-list'
-if there is no INFOPATH variable in the environment.")
+if there is no INFOPATH variable in the environment.
+The last element of `Info-default-directory-list' is the directory
+where Emacs's installs the Info files that come with it.
+If Emacs finds it has been installed elsewhere, or not yet installed,
+it replaces that element with the directory that its Info files are in.")
(defvar Info-current-file nil
"Info file that Info is now looking at, or nil.")