Browser sellers could integrate this type of information so as to warn the consumer when certification for a domain name is issued by a CA which hasn’t issued certificates to its corresponding domain up to now. This strategy may have effects for user groups which use HTTPS websites which use a certificate of those deleted CAs. CAS delivers online certificates for a small number of domains and that certificates are used by the domains in most domains from a set of CAs. So as to lower the danger, CAs may be limited to particular top-level domain names. Some CAs seem to work for one organization in one state only.