website rules for 501c3 organization

Who is paying for the domain? If he is paying for it as a contribution then the link would be OK. Otherwise, it should be removed. However, there is nothing wrong with him taking credit for the design and listing his URL as part of that.

I did check out the site and don't see anything untoward.

Scott,
I read a similar problem from another 501c3 corp. The answer was that while it might be legal, it was unethical. I believe the domain is no charge, which is the reason and problem for the severe limitations.

Our Mission is to promote the local venues and musicians. Something he refuses to do. Instead he promotes his own business, using one of the few available links. Members and non-members has taken umbrage. The previous Blues Society, whose 501c3 we were able to capture, had a very bad reputation for manipulation, such as this. The IRS segment on Not For Profits says "private benefit" and "inurement" as no-nos. We are an all volunteer group. In many cases, putting up our own money to keep things going.

Again, if he is donating the web hosting, then I think he is entitled. But the bottom line is if you don't want the link, then tell him to remove it. If he refuses then get a different web host.