TLD Registry Ltd (referred to in this policy document as “TLD Registry” or with the pronoun “us”) is the exclusive operator of two Top Level Domains (TLDs), Dot Chinese Online (.在线) and Dot Chinese Website (.中文网). Both our TLDs have been created for the express purpose of encouraging the use of all contemporary forms of Chinese Language in Internationalized Domain Names (IDNs). Our Registry Agreement (RA) with the internet’s governing body for domain names, the Internet Corporation for Assigned Names and Numbers (ICANN), allows Chinese Language in all Dot Chinese Online & Dot Chinese Website domain names.

The policies which follow this introduction define our rules for IDN registrations, and provide examples of the various forms of Chinese Language in contemporary use.

IDN Compliance

TLD Registry fully complies with all relevant Internet Engineering Task Force (IETF), International Standards Organization (ISO), ICANN and other internet standards as well as the ICANN RA which empowers us to register IDNs in our TLDs. Relevant internet standards include IETF RFCs which comprise IDNA2008 (RFC 5890, RFC 5891, RFC 5892, RFC 5893, RFC 5894). Our use of Unicode Points in our IDNs is fully compliant with relevant standards.

Chinese Language

TLD Registry’s RA with ICANN approves the use of “Chinese Language” in our IDNs.

Chinese Language comprises hundreds of dialects of the common language metagroup known as Chinese. The overwhelming majority of Chinese speakers use the Mandarin or Cantonese dialects. Mandarin Chinese is typically written in Simplified Chinese characters in China’s mainland, and in Traditional Chinese characters in Taiwan and some other parts of the Chinese-speaking world. Mandarin is also written in the Mandarin Pinyin romanization system, and as such uses ASCII characters. Pinyin is in ubiquitous use in China’s mainland and worldwide – it is the first form of Chinese which every mainland Chinese child is taught. Regardless that Mandarin Pinyin is written in ASCII characters, it is not English. It is a pure and Chinese-government-standardized form of Mandarin Chinese.

Cantonese is the dominant form of Chinese in the southern parts of China’s mainland, Hong Kong, Macau, and most “Chinatowns” around the world. Cantonese is typically written in Traditional Chinese characters. In systems analogous to Mandarin Pinyin, Cantonese is commonly romanized using ASCII characters. The major forms of romanized Cantonese include without exception Barnett-Chao, Meyer-Wempe, Standard, Guangdong Romanization, Hong Kong Government Romanization, Yale, and Jyutping.

TLD Registry is committed to supporting the increased use of Chinese Language on the internet, and our policy is one of inclusiveness for all Chinese Language users, regardless of their preferred variant of Chinese Language. IDNs in Dot Chinese Online (.在线) and Dot Chinese Website (.中文网) may be formed from any instance of Chinese Language.

How our IDNs are registered

Our Shared Registration System (SRS) enables the creation of IDNs that contain Chinese Language Unicode characters or Romanized Chinese Language in ASCII characters. The numerals 1, 2, 3, 4, 5, 6, 7, 8, 9, 0 and the hyphen character (-) are also allowed.

IDN registrations are tested against the allowable Chinese and ASCII characters contained in our IDN Tables, and if those characters appear in the IDN Tables, and the order of characters constitutes a unique and allowable IDN, the IDN will be registered with the Language Tag “Chinese / ZH”.

All forms of Chinese Language are included in the Language Tag “Chinese / ZH” (such as Simplified Chinese aka Hanzi, Traditional Chinese aka Fantizi, Pinyin, Guobao, BIG5, etc.) In principle, we are committed to empowering contemporary Chinese Language by allowing as many unique characters as possible, and our IDN Tables reflect this policy.

Please refer to our IDN Tables for a detailed presentation of allowable characters.

Chinese Character Variants

Our policy for Chinese Character Variants is key for allowing or disallowing certain IDN registrations.

In layman’s terms, a “Variant Set” is a group of Chinese characters which use similar but different visual representations of the same character. Variants exist in Chinese Language due to the ancient and rich development of the Chinese writing system over some 5000 years.

When one variant of a Chinese character is registered in a unique IDN, the IDN becomes canonical, and other IDNs using variant characters in the same position become Blocked and will not resolve. If a canonical IDN expires and is not renewed by the Registrant, the IDN and all variants of that IDN become available for a new registration.

Please refer to our IDN Tables for a detailed presentation of our Variant Sets.

English and non-Chinese words

It is a feature of contemporary Chinese Language that many English and some other-language words have entered the popular lexicon. Hundreds of millions of Chinese citizens and ethnic Chinese people have incorporated these loan words into their Chinese. Further, some brands have elected to go-to-market in Chinese regions with their English or non-Chinese brand names ("IBM" is an example).

As our mission is to reflect contemporary Chinese in all its forms, so as to empower Chinese speakers to use their own language online, we permit such loan words to be registered.

Permissible number of characters in our IDNs

Single character IDNs, using Simplified or Traditional Chinese characters, are permissible if compliant with our IDN policies. This is because single Chinese characters are analogous to multi-character English words, and to disallow single character Chinese IDNs would eliminate approximately 40% of Chinese words in contemporary use.

Single and two-character IDNs using ASCII characters are not permissible.

The maximum number of characters which our IDNs support, whether written in Simplified or Traditional Chinese characters or ASCII is 63.

The hyphen character (-) is not permissible in the first, third or forth position in any of our IDNs. It is permissible in any other position.

Prohibited and Reserved IDNs

ICANN requires us to Reserve certain IDNs to ensure predictable operation of the global Domain Name System (DNS).

We reserve the right to prohibit certain IDNs which may not be compliant with the laws of the countries we support. Our decision on such prohibited IDNs is final.

Some IDNs are Reserved by us for special purposes, such as IDNs Reserved as Premium Domain Names, or for special use in our Registry’s operations.

Link to the IDN Table for .在线 (Dot Chinese Online)

Link to the IDN Table for .中文网 (Dot Chinese Website)

Policy version 1.2 / Updated 9th April, 2014.


Changelog version 1.1: additional policy added to clarify permissible length of our IDNs and permissible use of hyphen character (-).

Changelog version 1.2: clarified the permissible nature of non-Chinese loan words; added explainer infographic.

This post is also available in: Chinese (Simplified), Chinese (Traditional)