The first argument is a format control string, and the rest are data
to be formatted under control of the string. See `format' for details.
+Note: Use (message "%s" VALUE) to print the value of expressions and
+variables to avoid accidentally interpreting `%' as format specifiers.
+
If the first argument is nil or the empty string, the function clears
any existing message; this lets the minibuffer contents show. See
also `current-message'.