At one point, .bz domains were being marketed by an American company as standing for "business", and that company took legal action against ICANN in an attempt to block the .biz domain as "unfair competition". Currently, the registry is in Belize, but is still marketing the domain outside the country as "meaning business". Internationalised domains with a wide assortment of non-ASCII characters are also available.
A lot of websites in Italy use this domain, because the abbreviation of Bolzano (de. Bozen) and the official abbreviation of the province of Bolzano-Bozen is BZ. Many websites use the Italian subdomain .bz.it. Servers for the Open Source game BZFlag often use names ending in .bz.
There are some second-level domains in use, however these are not required: