Keep a record of membership requests - especially those denied

I just noticed that there's detailed information available about the people who request membership. If I deny them membership, I lose that information. And yet, they're often people I'd want to connect with in other ways (e.g., they can't actually join the group, but want periodic updates about our activities). Since I was offered the opportunity to "mark" the request as approved or denied, I didn't expect it to disappear altogether when I denied it. I would prefer to have a record of memberships requested and denied.