This function ignores any arguments and returns @code{nil}.
@end defun
+ Emacs Lisp functions can also be user-visible @dfn{commands}. A
+command is a function that has an @dfn{interactive} specification.
+You may want to call these functions as if they were called
+interactively. See @ref{Interactive Call} for details on how to do
+that.
+
@node Mapping Functions
@section Mapping Functions
@cindex mapping functions