public function remove_keyword_group ($key) {
        //Remove the keyword group internally
        unset($this->language_data['KEYWORDS'][$key]);
        unset($this->lexic_permissions['KEYWORDS'][$key]);
        unset($this->language_data['CASE_SENSITIVE'][$key]);
        unset($this->language_data['STYLES']['KEYWORDS'][$key]);

        //NEW in 1.0.8
        unset($this->language_data['CACHED_KEYWORD_LISTS'][$key]);
    }