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Universal Acceptance Training

To raise awareness of Universal Acceptance (UA) challenges and to provide solutions for stakeholders, ICANN and the Universal Acceptance Steering Group (UASG) support training on a variety of UA-related topics, including Email Address Internationalization (EAI).

ICANN Learn Course

The "Introduction to Universal Acceptance" course is intended for a wide audience including the general Internet community, technology enablers and developers, email service providers, governments, and policymakers.

This course provides participants with a basic understanding of UA and its technical challenges, the current state of UA-readiness globally, and the economic and social benefits of being UA-ready.

To take the course, register for an ICANN account and then select the free UA course at Upon completion of the course, you will receive a certificate.

Regional UA Training Programs

Each regional program provides training on the technical aspects of UA and serves as a forum to discuss how to effectively address UA issues specific to the region. Regardless of where the training sessions are held, you can register to attend or listen to the recordings.

UA Technical Training Materials

UA training materials are available for Java and Python developers. EAI training materials are available for system administrators, including information on how to set up an email server to support EAI.

Domain Name System
Internationalized Domain Name ,IDN,"IDNs are domain names that include characters used in the local representation of languages that are not written with the twenty-six letters of the basic Latin alphabet ""a-z"". An IDN can contain Latin letters with diacritical marks, as required by many European languages, or may consist of characters from non-Latin scripts such as Arabic or Chinese. Many languages also use other types of digits than the European ""0-9"". The basic Latin alphabet together with the European-Arabic digits are, for the purpose of domain names, termed ""ASCII characters"" (ASCII = American Standard Code for Information Interchange). These are also included in the broader range of ""Unicode characters"" that provides the basis for IDNs. The ""hostname rule"" requires that all domain names of the type under consideration here are stored in the DNS using only the ASCII characters listed above, with the one further addition of the hyphen ""-"". The Unicode form of an IDN therefore requires special encoding before it is entered into the DNS. The following terminology is used when distinguishing between these forms: A domain name consists of a series of ""labels"" (separated by ""dots""). The ASCII form of an IDN label is termed an ""A-label"". All operations defined in the DNS protocol use A-labels exclusively. The Unicode form, which a user expects to be displayed, is termed a ""U-label"". The difference may be illustrated with the Hindi word for ""test"" — परीका — appearing here as a U-label would (in the Devanagari script). A special form of ""ASCII compatible encoding"" (abbreviated ACE) is applied to this to produce the corresponding A-label: xn--11b5bs1di. A domain name that only includes ASCII letters, digits, and hyphens is termed an ""LDH label"". Although the definitions of A-labels and LDH-labels overlap, a name consisting exclusively of LDH labels, such as"""" is not an IDN."