Hi, a simple question... if I register the Virgin domain name under the .xxx extension it would be copyright infringement? Note that this is just an example. The word virgin is a common word and I think it cannot be copyrighted...
You're correct that a common word can't be copyrighted. OTOH, it can be used as a trademark, which is probably what you're really referring to. Any word, even if used in everyday english, can be a trademark if it's used distinctively rather than descriptively. Virgin may be a common word, but I guess you haven't heard of, say, Virgin Records, Virgin Cola or Virgin America? Registering domain names per se doesn't necessarily infringe, though. It's what you intend to do with it that might get you into trouble, namely using it to make money in any way off of its TM namesake without their permission. I don't know if Sir Richard Branson's Virgin group is interested in investing in anything possibly sexual.
As long as you don't do anything to violate the trademarks of companies with virgin in their names, you are ok. Virgin is a common word that cannot be trademarked or copyrighted. Only the distinctive use of the word (e.g. branding) can be trademarked or copyrighted.
If registering virgin.xxx is an infringement of the Virgin Group's copyright, then registering apple.xxx would also be an infringement, wouldn't it? Ditto for orange.xxx, right?
Trademarked, definitely. I once reg minidonuts.com and got a letter from BMWUSA for the trademarked word "mini" and had to let it go to them. So no need to say more about just one word which is trademarked as virgin... Make a search on the trademark and go from there. They are literally billions of trademarked words...