Domain Name Restrictions:
".co.uk" and ".org.uk" domains.
(A) Characters allowed: -abcdefghijklmnopqrstuvwxyz0123456789
(B) .co.uk and org.uk names can be up to 63 Characters.
(C) Must not begin or end with a hyphen.
".ltd.uk" and ".plc.uk" domains.
(A) Characters allowed: -abcdefghijklmnopqrstuvwxyz0123456789
(B) .co.uk and org.uk names can be up to 63 Characters.
(C) Must not begin or end with a hyphen.
".com", ".net" or ".org" domains.
(A) Characters allowed: -abcdefghijklmnopqrstuvwxyz0123456789
(B) .com, .net and .org names can be up to 67 Characters.
(C) Must not begin or end with a hyphen.
".info" and ".biz" domains.
(A) Characters allowed: -abcdefghijklmnopqrstuvwxyz0123456789
(B) .info, and .biz names can be up to 63 Characters, excluding the .info or .biz portion, but they can't be shorter than 3 characters in length. (All one and two letters domains are not allowed, e.g., z.info or z.biz and zz.info or zz.biz).
(C) Must not begin or end with a hyphen or have hyphens in the third and fourth character positions, e.g., you cannot have zz-abcdef.info or zzz-abcdef.biz.
Restrictions on the use of:
".ltd.uk" and ".plc.uk" domains.
(A) These can only be registered by and for a company registered at Companies House or on the Company Registry in Northern Ireland.
(B) The following words cannot be included in the domain name: Limited or Public Limited Company and the Welsh Versions, along with abbreviations of these words ie ltd, plc & ccc..
".info" and ".biz" domains.
(A) Anyone may register an ".info" domain name for any purpose; there are no restrictions.
(B) But a ".biz" domain name can only be used for a "bona fide business or commercial use"; this rules out registrants obtaining a domain name solely to sell, trade or rent, or to use it for non commercial activities or to express "anti business" ideas.
".org" and ".org.uk" domains.
(A) .org and .org.uk domains MAY at some future date be only renewable for use by non profit organisations, and their use to promote commercial services may be curtailed.