Following their approval back in March, porn and adult entertainment sites can now officially register web addresses under the .xxx top-level domain. The ICM Registry, working with around 50 individual registrars around the world, is kicking off a 52-day "sunrise" period for companies both in and outside the adult industry to register for or block themselves from the domain before .xxx is open to the public.

The 52-day period is open until October 28 and will run on two tracks: Sunrise A will handle registrations from existing adult sites that want to buy the .xxx version of their domains in order to protect their brand, while Sunrise B will target companies outside the online porn industry who don't want their businesses associated with a porn-focused domain. Domain pricing starts at around $100 per year for the first group, plus an application fee the first year that costs between $80 and $110. Those protecting their trademarks by "opting-out" can pay a one-time fee of around $200.

After that, a "land rush" period will start on November 8 for those in the adult entertainment community who don't own a trademark to protect but want to secure a valued .xxx domain name and avoid first come, first served general availability risks. Everyone else can start snagging .xxx domains after December 6 when it opens to the public.

The approval of .xxx TLDs didn't come without controversy and, ironically, many in the porn industry were opposing the move. Not only are they worried that an .xxx site could be easily filtered, making their investment worthless, but they also don't want to pay for new .xxx domain names to protect brands that they built with .com names.

It should be noted that .xxx domains won't be mandatory for sites with adult content, and porn site owners that do purchase one of these domains won't have to relinquish their .com or other URLs.

For its part ICM argues that .xxx domains will allow a clearly defined Web address for adult entertainment, out of the reach of minors and as free as possible from fraud or malicious computer viruses, while webmasters will see more traffic and higher profits with the new domain which is to become a trusted brand.