<p>A domain name that you want to use as the basis for a list of possible domain names. The top-level domain (TLD), such as .com, must be a TLD that Route 53 supports. For a list of supported TLDs, see <a href="https://docs.aws.amazon.com/Route53/latest/DeveloperGuide/registrar-tld-list.html">Domains that You Can Register with Amazon Route 53</a> in the <i>Amazon Route 53 Developer Guide</i>.</p> <p>The domain name can contain only the following characters:</p> <ul> <li> <p>Letters a through z. Domain names are not case sensitive.</p> </li> <li> <p>Numbers 0 through 9.</p> </li> <li> <p>Hyphen (-). You can't specify a hyphen at the beginning or end of a label. </p> </li> <li> <p>Period (.) to separate the labels in the name, such as the <code>.</code> in <code>example.com</code>.</p> </li> </ul> <p>Internationalized domain names are not supported for some top-level domains. To determine whether the TLD that you want to use supports internationalized domain names, see <a href="https://docs.aws.amazon.com/Route53/latest/DeveloperGuide/registrar-tld-list.html">Domains that You Can Register with Amazon Route 53</a>. </p>