I don't think I've ever seen PARAM_CHAR be used, there are alternatives, PARAM_ALPHANUMEXT comes to mind. Check out lib/moodlelib.php for available PARAM_ types.
It's possible it was on an older version of Moodle, I did a quick look but couldn't see it ever existed.
It's possible it was on an older version of Moodle, I did a quick look but couldn't see it ever existed.