all you need to know about domain names
(and some you don't need to know, but is interesting anyway)
CHAPTER 1.04
WHAT CHARACTERS CAN YOU USE IN A DOMAIN NAME?
There is an unambiguous limit to the characters that can be used in a domain name. They are: all the letters of the Latin alphabet (A to Z) plus any number (0 to 9) and a hyphen (-). No spaces or other characters are allowed in a domain name. Note, however that these rules apply to domain names that use the English language. Others, known as Internationalized Domain Names, are available in different languages - these are covered in more detail in chapter 1.05. A domain name must begin and end with a letter or a number. Any amount of hyphens can be used, but must not be placed together. Domain names must be at least three and less than 63 characters in length (excluding suffixes).
Although two letter domains do exist, they are only allocated to organizations that can prove that they are universally recognized by a two character name. Hewlett Packard uses hp.com, for example, General Electric ge.com and UK communications giant O2 use o2.co.uk. Realistically, however, unless you are in the same league as these examples, you can forget two character domains. Even rarer - and less-available - are single-character domain names. For example, z.com is owned by Nissan (it redirects to nissanusa.com/z), q.com is owned by Qwest (redirects to qwest.com), x.com is owned by PayPal labs and g.cn takes you to google.cn. Quite how these sneaked through I do not know - but do not get the idea that single character domains on the main suffixes are an option for you. However, the summer of 2009 saw .biz domains become available on single and two character options. Whilst I am not convinced that ac.biz is a good domain for me or anything similar effective for other organizations, I would make two points, (i) it may be an indication of what other suffixes might make available in the future, and (ii) maybe a new business, could develop a new brand might around a single character .biz name. Buyers, however, seem to share my doubts, with only 5 of the 36 available single-character names being taken up in the original release. The most significant of these being overstock.com who registered o.biz for a B2B-only version of their service (note, that is 'o' for overstock, though they have also - sensibly - registered 0.biz, ie zero.biz).
Certain words are not permitted to be registered. These are the so-called '7 filthy words' that US Network TV and radio companies won't broadcast [For obvious reasons, I'll not list them here - if you can't guess them, simply type "7 filthy words" into a search engine.]. This ruling originates from a court decision following a New York radio station's broadcast (in 1973) of a 12-minute monologue entitled 'Filthy Words' which had been recorded earlier by a satiric humorist called George Carlin. So outraged were listeners that the major TV and radio networks agreed a ban on the seven words that caused such offence (if you are now thinking that you have heard bad language on American TV shows you will find that those programmes - Sex and the City, for example - are broadcast on Home Box Office (HBO) and not networked channels). Whilst this ban is closely policed by domain authorities, sometimes the odd word sneaks through (an example is featured in chapter 2.02).
The maximum number of characters that can be used in a single domain name is restricted by the relevant naming authority. The majority of these (many do not actually declare any limitations on their web pages) follow the .com rule of up 63 characters before the suffix (note that the http:// and any second/third level names eg www, are not included as they are not part of the actual domain name). Domain names for commercial use should never reach this limit, though - as usual - there will always be exceptions to this rule. For example, the imaginatively named 'the longest list of the longest stuff at the longest domain name at long last' website - can be found on
thelongestlistofthelongeststuffatthelongestdomainnameatlonglast.com
- in this case using all 63 characters in the domain name reflects the content of the site.
Finally - and this is important for marketing reasons that will be covered later - domain names are NOT case sensitive. From a technically standpoint, it is possible to set up a website's host server so that it recognizes upper and lower case characters in a domain name - so making a domain case sensitive. However, I have never seen this practiced - it being the standard operating procedure to set them up as being non-case sensitive. I have even spoken to techies who do not realise it is even possible to have case sensitive domain names. The same applies to email addresses. Once again, the default is to set up the email address to be non-case sensitive - and though I have come across one case sensitive email address (at a University in Northern Ireland) - the practice is ubiquitous. Even so it comes as a surprise to many people that email addresses are not case sensitive - you must have heard something like 'yes my email address is alan.charlesworth@atrustingbusiness.com, that's lower case a-l-a-n ...'. Or maybe you have done it yourself? Still doing it? Not after you have read this you won't. Not really a domain name issue - but take this as an added bonus - whilst characters in a domain name are restricted, this is not the case in the before-the-@ element of an email address. Yes I could have %#1000@alancharlesworth.com - but it would be very confusing for users, and so is not a good idea.
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