But I'm sure the USGN check thing would work. Unless, of course, someone's registered two of those.
I'm sure lots of people are in more than one clan. Their profile should just keep a nice, tidy list for those.
The screenie looks like there has yet to be a forum. Are you planning on adding one of them newfangled message boards on the site? This would facilitate the informing more than PMs to everyone in the clan could for sure.
glhf on the site.