Disclaimer: I am not an attorney.
I trademarked my domain name, which is also the name of a magazine I used to publish. In the trademark papers I had to state specifically what the name is used to.
It is listed as so at the USPTO website:
"GOODS AND/OR SERVICES
---------------------------------------------------------------------------Entertainment services, namely, providing adult oriented photographs via the Internet"
Now -- from the way the trademark attorney explained it to me, someone else can trademark that name and use it for a totally different reason. Actually, it IS trademarked to someone else, but for a cosmetic product that's the same name. But since I don't use it for that reason, I'm allowed a trademark as well.
Even though I own the trademark for XXXX, you can still register XXXX.org and use it AS LONG as the site isn't used for "Entertainment services, namely, providing adult oriented photographs via the Internet".
But, if you register XXXX.org for the same type of website, I can then sue you for trademark infringement.