域名中不能含有_

您输入的域名不符合域名注册规则，请重新输入

提示：域名可由英文字母（a-z，不区分大小写）、数字（0-9）、中文汉字以及连字符"-"（即中横线）构成，不能使用空格及特殊字符（如！、$、&、?等）。“-” 不能单独注册或连续使用，不能放在开头或结尾。

 

 

其实这里有个RFC 952规范 - 美国国防部互联网主机表规范中的相关条文：

A "name" (Net, Host, Gateway, or Domain name) is a text string up to 24 characters drawn from the alphabet (A-Z), digits (0-9), minus sign (-), and period (.)

//规范指出域名只能是字母、数字和短线（-）还有点（.）。

AG Domain Name Rules Summary

Click here for Blocked or Reserved Domain Names Policy

1. Use only letters, numbers, or hyphen ("-")
2. Domain names cannot begin or end with a hyphen
3. Domain names cannot have more than 63 characters, not including .AG, .COM.AG, .NET.AG, .ORG.AG, .EDU.AG, .GOV.AG, ETC.
4. Maximum length of a complete (Fully Qualified, FQDN) domain name (including .separators) is 255 characters
5. Minimum length of a domain name is 1 character, not including extensions. However, all 1 character domain names are reserved by the Registry.
6. A name may begin with a digit
7. Two character domain names are allowed
8. Domain names considered offensive may be declined
9. For domains to be active on the Internet, they must have at least one configured and working name server.
10. There is no restriction on the physical location or IP address of these name servers.
11. Domain names may be re-sold
12. A domain name registration shall be for at least an initial 1 year period, and should be renewed at least annually thereafter.
13. A domain name can initially be registered for 1-10 years period
14. A domain name can be renewed for 1-10 years period
15. A domain name registration period cannot exceed 10 years
16. There is no restriction on the number of domain names that a single entity or person can register.
17. A domain name may be revoked if it is used for offensive, immoral or illegal purposes, including "Spam".
18. A domain name may be revoked if found to be in contravention of published policies and procedures
19. A domain name may be suspended or revoked if Nic AG is directed by a court of competent jurisdiction.
20. Nic AG will use reasonable efforts to make the Name Service available at all times. However, the quality and availability of the service may be affected by factors outside our control such as but not limited to: fire, flood and subsidence, physical obstructions, atmospheric conditions, acts of God, industrial action, default or failure of a third party. The service may also be affected by faults in national and international telecommunication networks on which the service may rely.
21. The registration of a new name is usually immediate and automated.
22. .ag, .com.ag, .net.ag, and .org.ag are currently available to any and all registrants worldwide for the stated fees.
23. .edu.ag is available ONLY to valid local Antiguan and Barbudan Educational Institutions.
24. .gov.ag is available ONLY to valid local Antiguan and Barbudan Government departments, agencies, ministries, etc.
25. In the case of restricted second or third level domains (such as .edu.ag and .gov.ag), applicants may be asked to provide proof of their identity, or details of their existence as a properly constituted Antiguan organisation, and evidence of their ability to meet the conditions for holding such a domain name.
26. For the purposes of registration policies and prices, Antiguan "offshore" or "International" companies are not considered local Antiguan entities. Nic AG will use established laws and government policies to determine who or what constitues Antiguan entities.
27. Upon application for registration of a new domain name, name holders agree to be bound by all published policies and terms of service. Where the name holder makes use of an agent, the agent agrees that it has made its client aware of all policies - and - that the client agrees to be bound by those policies.
28. If there is conflict between an applicant for a new domain name and the holder of an existing name, it is for those parties to resolve the conflict. Any resulting change in registration details of the existing name must be mutually agreed between the parties.
29. Nic AG does not decide whether an applicant has a legitimate right to the name. The applicant, in lodging the request for the name, warrants that it is entitled to register the name as requested.
30. Applicants who misrepresent their entitlement to register or use a name are warned that this may result in action from others who claim rights to the name. If Nic AG, or any of their agents, officers or employees incur costs through involvement in disputes over names, any applicant for, or holder of, a name which is subject to a dispute will be liable for those costs.
31. A domain name may be cancelled or redelegated at any stage where the name holder does not comply with these requirements or fails to meet any fees or other liabilities in connection with the registration or use of the domain name.
32. Nic AG reserves the right to change any and all policies at any time, providing that such policy changes become effective upon posting on this and other websites.