The following is a list of rules of each registry. Please note that this list may not be a complete list and that each registry may adopt additional rules from time to time.  Domain Names have a variety of basic rules:

 GENERAL EXTENSIONS

.COM, .NET and .ORG Domain Names

• .COM - to be used for commercial and personal sites
• .NET - recommended for companies involved in Internet infrastructure
• .ORG - recommended for not-for-profit organizations
• Use only letters, numbers, or hyphen ("-")
• Cannot begin or end with a hyphen
• Must have less than 63* characters, not including .COM, .NET and .ORG

* .com, .net and .org domain names exceeding a total of 26 characters are supported by most web browsers. However, certain web browsers, email programs and other Internet related applications may not support domain names over 26 characters.

 .INFO Domain Names

• .INFO - to be used for both commercial and personal sites
• Use only letters, numbers, or hyphen ("-")
• Cannot begin or end with a hyphen
• Must have at least 3 characters and less than 63 characters, not including .INFO

 .BIZ Domain Names

• .BIZ - sites restricted to commercial and bona fide business purposes
• Use only letters, numbers, or hyphen ("-")
• Cannot begin or end with a hyphen
• Cannot have two hyphens in a row
• Must have at least 3 characters and less than 63 characters, not including .BIZ

 .NAME Domain Names

• .NAME - to be used for personal sites
• Must be composed of a first and last name (yourname1.yourname2.name)
• First name (yourname1 in above example) must have at least 1 character and no more than 63 characters
• Second name (yourname2 in above example) must have at least 3 characters and no more than 63 characters
• Use only letters, numbers or hyphen ("-")
• Cannot begin or end with a hyphen
• Note** Not available for new registration

COUNTRY-SPECIFIC EXTENSIONS

.AC and .SH Domain Names

• .SH - St. Helena, to be used for both commercial and personal sites
• .AC - Ascension Island, to be used for both commercial and personal sites
• Use only letters, numbers, or hyphen ("-")
• Cannot begin or end with a hyphen
• Must have at least 3 characters, but less than 23, not including .AC and .SH

 .AS Domain Names

• .AS - American Samoa, to be used for commercial and personal sites
• Use only letters, numbers, or hyphen ("-")
• Cannot begin or end with a hyphen
• Must have at least 3 characters, but less than 23, not including .AS

 .BE Domain Names

• .BE - Belgium, to be used for commercial and personal sites
• Use only letters, numbers, or hyphen ("-")
• Cannot begin or end with a hyphen
• Must have at least 2 characters, not including .BE

 .CA Domain Names

• .CA registrants must meet Canadian presence requirements as defined by CIRA (Canadian Internet Registration Authority) 
• Use only letters, numbers, or hyphen ("-")
• Cannot begin or end with a hyphen
• Length. Domain names must be not less than two (2) and not greater than fifty (50) characters long.

 .CC Domain Names

• .CC - Cocos (Keeling) Islands, to be used for commercial and personal sites
• Use only letters, numbers, or hyphen ("-")
• Cannot begin or end with a hyphen
• Cannot contain all numbers
• Must have at least 3 characters, but less than 47, not including .CC

 .CO.IL and ORG.IL Domain Names

• .CO.IL - Israel, to be used for commercial and personal sites
• .ORG.IL - Israel, to be used for commercial and personal sites
• Use only letters, numbers, or hyphen ("-")
• Cannot begin or end with a hyphen
• Must have as few as three and as many as 62 characters, not including .IL
• No more than 10 domain names may be registered by any individual or organization.

 .CO.UK and .ORG.UK Domain Names

• .CO.UK - United Kingdom TLD used for both commercial and personal sites
• .ORG.UK - United Kingdom TLD used for both commercial and personal sites
• Use only letters, numbers, or hyphen ("-")
• Cannot begin or end with a hyphen
• Must have at least 3 characters, but less than 23, not including .CO.UK and .ORG.UK

 .DE Domain Names

• .DE - Germany, to be used for commercial and personal sites
• Use only letters, numbers, or hyphen ("-")
• Cannot begin or end with a hyphen
• Must have at least 3 characters, but less than 64, not including .DE

 .DK Domain Names

• .DK - Denmark, to be used for commercial and personal sites
• Use only letters, numbers, or hyphen ("-")
• Cannot begin or end with a hyphen
• Must have less than 23 characters, not including .DK

 .FM Domain Names

• .FM - Micronesia, to be used for commercial and personal sites
• Use only letters, numbers, or hyphen ("-")
• Cannot begin or end with a hyphen
• Must have less than 23 characters, not including .FM

 .JP Domain Names

• .JP - Japan, to be used for commercial and personal sites
• Use only letters, numbers, or hyphen ("-")
• Cannot begin or end with a hyphen
• Must have at least 3 characters, but less than 63, not including .jp

 .KZ Domain Names

• .KZ - Kazakstan, to be used for commercial and personal sites
• Use only letters, numbers, or hyphen ("-")
• Cannot begin or end with a hyphen
• Must have less than 23 characters, not including .KZ

 .LT Domain Names

• .LT - Lithuania, to be used for commercial and personal sites
• Use only letters, numbers, or hyphen ("-")
• Cannot begin or end with a hyphen
• Must have at least 3 characters, but less than 23, not including .LT

 .MS, .VG, .TC, .GS and .TF Domain Names

• .MS - Montserrat, to be used for both commercial and personal sites
• .VG - British Virgin Islands, to be used for both commercial and personal sites
• .TC - Turks and Caicos Islands, to be used for both commercial and personal sites
• .GS - South Georgia & South Sandwich Islands, to be used for both commercial and personal sites
• .TF - French Southern Territories, to be used for both commercial and personal sites
• Use only letters, numbers, or hyphen ("-")
• Cannot begin or end with a hyphen
• Must have less than 23 characters, not including .MS, .VG, .TC, .GS and .TF

 .NZ Domain Names

• .CO.NZ - New Zealand, intended organizations pursuing commercial aims & purposes
• .NET.NZ - New Zealand, intended organizations or services providers related to the NZ internet
• .ORG.NZ - New Zealand, intended for non-profit organizations
• Use only letters, numbers, or hyphen ("-")
• Cannot begin or end with a hyphen
• Must have less than 23 characters, not including .CO.NZ, .ORG.NZ, and .NET.NZ

 .PH Domain Names

• .PH and .COM.PH - Philippines, to be used for commercial and personal sites.
• Use only letters, numbers, or hyphen ("-")
• Cannot begin or end with a hyphen
• Must have as few as three and as many as 62 characters, not including .com.ph or .ph

 .RO Domain Names

• .RO, .COM.RO - Romania, to be used for commercial and personal sites
• Use only letters, numbers, or hyphen ("-")
• Cannot begin or end with a hyphen
• Must have less than 23 characters, not including .RO

 .ST(SiTe) Domain Names

• .ST(SiTe) - São Tomé and Principe, to be used for commercial and personal sites
• Use only letters, numbers, or hyphen ("-")
• Cannot begin or end with a hyphen
• Must have as few as one and as many as 23 characters, not including .ST

 .TO Domain Names

• .TO - Tonga, to be used for commercial and personal sites
• Use only letters, numbers, or hyphen ("-")
• Cannot begin or end with a hyphen
• Must have less than 23 characters, not including .TO

 .TV Domain Names

• .TV - Tuvalu, to be used for commercial and personal sites
• Use only letters, numbers, or hyphen ("-")
• Cannot begin or end with a hyphen
• Must have less than 63 characters, not including .TV

 .US Domain Names

• .US - to be used by U.S. citizens and residents, U.S. corporations and other U.S. organizations and organizations with a presence within the United States
• Use only letters, numbers, or hyphen ("-")
• Domain names cannot begin or end with a hyphen
• Domain names must be longer than 2 characters and cannot exceed 63 characters (this does not include the extension)

 .WS Domain Names

• .WS - WebSite, to be used for commercial and personal sites
• Use only letters, numbers, or hyphen ("-")
• Cannot begin or end with a hyphen
• .WS domains registered through USHOSTMASTER.com must have as few as four and as many as 63 characters, not including the .WS extension

 .ZA Domain Names

• .CO.ZA - South Africa, to be used for commercial and personal sites
• Use only letters, numbers, or hyphen ("-")
• Cannot begin or end with a hyphen
• Must have less than 23 characters, not including .ZA