request a look-up and be automatically re-directed to the correct server(s). However, while the technical functionality is in place, adoption of the RWhois standard has been weak. RWhois services are typically communicated using the Transmission Control Protocol (TCP). Servers listen to requests on the well-known port number 4321. Rwhois was first specified in in 1994 by Network Solutions, but the specification was superseded in 1997 by . The referral features of RWhois are different than the feature of a Whois server to refer responses to another server, which RWhois also implements. Criticism One criticism of WHOIS is the lack of full access to the data. Few parties have realtime access to the complete databases. Others cite the competing goal of domain privacy as a criticism, although this problem is strongly mitigated by domain privacy services. Currently, the Internet Corporation for Assigned Names and Numbers (ICANN) broadly requires that the mailing address, phone number and e-mail address of those owning or administering a domain name to be made publicly available through the "WHOIS" directories. The registrant's (domain owner's) contact details, such as address and telephone number, are easily accessible to anyone who queries a WHOIS server. However, that policy enables spammers, direct marketers, identity thieves or other attackers to loot the directory for personal information about these people. Although ICANN has been exploring changing WHOIS to enable greater privacy, there is a lack of consensus among major stakeholders as to what type of change should be made. Some domain registrars offer private registrations (also known as domain privacy), by which the contact information of the registrar is shown instead of the customer's. With the offer of private registration from many registrars, some of the risk has been mitigated. Studies have shown that spammers can and do harvest plain-text email addresses from WHOIS servers. For this reason, some WHOIS servers and websites offering WHOIS queries have implemented rate-limiting systems, such as web-based CAPTCHA and limited amounts of search queries per user IP address. The WHOIS requirements conflict with the General Data Protection Regulation (GDPR), effective in the European Union 25 May 2018, which places strict regulations on the processing and publication of personally identifiable information. ICANN stated in November 2017 that it would not reprimand "noncompliance with contractual obligations related to the handling of registration data" if registrars provide alternative solutions for compliance with its rules, until the WHOIS requirements are updated