Whether it serves as your business's indispensable catalog of services or simply announces you to the universe, your Web site is important. Its content and design are likely paramount in your thoughts, but the single most telling element of any Web site for visitors is its domain name. These tips will help you keep tight control of your domain.

Avoid shady registrars: Once upon a time (back in the twentieth century), the only domain registrar was Network Solutions. Registering cost $35 a year, and it didn't cover Web site hosting, e-mail, or any other domain-related service. Now more than 500 registrars compete for your business, offering prices as low as $7 per year, along with multiyear deals. Many bundle site hosting, e-mail, URL forwarding (which redirects browsers who enter a domain name to a different URL), and other domain-related services.

All registrars are approved by the Internet Corporation for Assigned Names and Numbers, but that doesn't guarantee that you will enjoy a specified level of service, or even that the registrar is safe to use. As we went to press, the registrar RegisterFly was still offering its services online, even though it permanently lost the domains of thousands of customers and was unable to process the domain transfer requests of other customers due to mismanagement by a former CEO. Other registrars, especially some that offer the lowest prices, may be slow to respond when you need customer service. A way to find a good registrar is to consult one of several sites that offer user reviews of registrars, including NamePros' index of registrars, DNForum.com's Domain Registrar Reviews, and RegSelect.

Get a registrar with a spine: Thanks to its Super Bowl ads, GoDaddy.com is one of the biggest and most visible registrars, and it gets good marks for customer service. Nevertheless, following a complaint from MySpace, it reportedly pulled the plug on security Web site SecLists.org recently with only 52 seconds' notice. Getting the site back online took hours, according to its owner. Domain registrars are required by ICANN to refuse service to purveyors of spam, child pornography, trademark infringement, and other criminal content, but individual registrars may choose to yank your domain for any reason. If your site contains controversial content, ask potential registrars if they actively support principles of free speech, and see whether they have a history of responding to disputes and complaints deliberatively.

Own your domain: Make sure your name appears in the official WhoIs database record for your domain (see "Who's Who on the Web," below). An untrustworthy registrar may sell you a domain but enter its own name in the domain's database record. Or it may offer you a "private" domain registration, with your name, address, and phone number missing from where they would ordinarily appear in the record. Before you register a domain, make sure that the registrar lets you decide who is listed as the owner.

Lock your domain: ICANN's regulations state that a request to transfer your domain to another registrar must go through if the domain owner fails to respond to the request within five days. In other words, while you're soaking up the sun on your vacation, a shifty registrar could come and hijack your domain. Select a registrar that lets you block any attempted domain transfer until you specifically okay it. (Microsoft came close to losing its namesake domain a few years ago when it failed to pay a $35 renewal fee on time.)

Block squatters: Most registrars have a tool on their site that lets you enter a domain you're interested in to see whether it's available. An unscrupulous registrar could use your search criteria for domain warehouses or domain kiting--schemes in which speculators snap up and sit on domain names that are likely to generate ad traffic. To avoid losing your hoped-for domain, restrict your searches to reputable sites and tools.