Supported Versions: PHP 4, PHP 5, PHP 7, PHP 8
Convert all applicable characters to HTML entities
htmlentities(    string $string,    int $flags ENT_QUOTES ENT_SUBSTITUTE ENT_HTML401,    ?string $encoding null,    bool $double_encode true): string
    public function cleanRateLimiterKey($key)

    {

        return 
preg_replace('/&([a-z])[a-z]+;/i''$1'htmlentities($key));

    }

}