Domain Name Rules

Okay all of you geek-heads out there - I need your opinions and expertise.

I have a new client who needs to register for a new domain name. The domain name that they would like is not available for .com, but is available as .org.

Now I knot that traditionally, .org stands for organization. Is it limited to non-profit organizations only? My client is an event planning company. Do they qualify as a .org, and is that even important anymore?

Surprisingly, I''m having a hard time finding info about this on the net.
(not that I actually tried for too long - I realized it would probably be much faster and easier to just ask my blog peeps)

thanks!