The Associated Press

LISBON, Portugal -- The Internet Corporation for Assigned Names and Numbers, the Internet's key oversight agency, has voted down against a proposal to create a voluntary ".xxx" domain name for pornography sites.

Questions about the proposal and domain names in general:

Q: What are domain names?

A: Behind every machine connected to the Internet is a series of four numbers known as an Internet Protocol address. Domain names were created as an easy-to-remember shortcut -- it's much easier to remember "ap.org" than "165.1.59.220." When you type a domain name into a Web browser or an e-mail message, your computer checks a series of domain name servers to match the name to the equivalent numeric address.

Q: How many domain names are there?

A: There are currently 266 suffixes with a handful of others approved but not yet functional. Most are for specific countries or regions, such as ".fr" for France and even the legacy ".su" for the Soviet Union. Others are reserved for specific uses, such as ".mil" for the U.S. military and ".museum" for museums. Relatively few -- the most popular being ".com" -- are truly for global and universal use.

Q: How do names get added?

A: Most of the names date back to the system's creation in the 1980s. In 1998, the U.S. government, which funded much of the Internet's early development, selected ICANN to oversee Internet addressing policies, including the addition of domain names. ICANN approved the first major round of additions in 2000, selecting seven names but essentially rejecting ".xxx" and several others. ICANN opened a second round in 2004 and received bids for 10. ICANN also has approved region-specific codes, including ".eu" for the European Union and ".ps" for the Palestinian territories.

Q: Where would have ".xxx" fallen?

A: The current proposal grew out of the 2004 round of bids, which ICANN specifically restricted to "sponsored" names, meaning their use would be limited to a specific community, be it the travel industry or porn sites. ICM Registry LLC, a Florida startup founded by entrepreneurs with backgrounds in domain names and U.K. Internet companies, sought its creation.

Q: Why did the decision take so long?

A: Of the 10 applications, only ".xxx" and ".post" for postal services had remained pending. The ".xxx" was rejected Friday by the ICANN board in a 9-5 vote with one member abstaining. ICANN had rejected the ".xxx" proposal last May, but ICM came back with a new plan with more specifics. Even before that got a vote, ICM returned with yet another proposal to address concerns about ICANN's enforcement abilities and the independence of a nonprofit body that would set rules governing the domain's use. Each step meant a period for public commenting. Opposition was strong among many adult Web sites and religious groups.

Q: What happens now that the name has been rejected?

A: ICANN Chairman Vinton Cerf said that the ICM proposal was at an end and that it would no longer be considered. ICM could seek to have the decision reviewed through ICANN channels or file a lawsuit if it believes ICANN failed to follow its own guidelines. A new proposal could be offered in the next round, too. ICANN has yet to announce details on the next round.