On Sun, Nov 01, 2020 at 04:54:55PM +0000, jai-bholeki via Users list for the GNU Emacs text editor wrote:
> I have a function gets the beginning and end of a region.
> 
> Is is possible to pass another argument to the function that is a character 'ch'?
> 
> (defun pengo (beg end)
> (interactive "r") ; Specifies Mark and Point, smallest first
> (goto-char beg)
> )

You mean something like this?

  (defun foo (beg end ch)
    (interactive "rRegion:\ncChar:")
    (message "Region: (%d, %d) Char: %c" beg end ch))

(i.e. separate consecutive args in the interactive specification with
a new line, `\n').

Cheers
 - t