public function check_shortname_collision($shortnamemark = '[*]') {
        global $DB;

        if ($this->properties->collision !== null) {
            return $this->properties->collision;
        }

        if (empty($this->properties->shortname)) {
            debugging('Attempting to check a course request shortname before it has been set', DEBUG_DEVELOPER);
            $this->properties->collision = false;
        } else if ($DB->record_exists('course', array('shortname' => $this->properties->shortname))) {
            if (!empty($shortnamemark)) {
                $this->properties->shortname .= ' '.$shortnamemark;
            }
            $this->properties->collision = true;
        } else {
            $this->properties->collision = false;
        }
        return $this->properties->collision;
    }