The opposite of a FQDN is a relative domain name like www or www.namesurfer, where one or more parent domain labels have been omitted for convenience or brevity.

NameSurfer allows the use of relative domain names only in certain places where it can determine the correct parent domain from the context. Otherwise, FQDNs must be used.

Binary labels as specified in RFC 2673 ("Binary Labels in the Domain Name System") might be used in NameSurfer as well as traditional labels.

Some other DNS software, BIND for example, requires you to write a trailing period after each FQDN (as in "www.namesurfer.com."). The NameSurfer WWW user interface also allows you to include this trailing period, but does not require it. The only exception is the root domain, which must be entered as ".", not as the empty string.