See rescinded invitations
There are lots of spammers out there. I get 4 to 5 unsolicited chats per day. The spammers have become smarter and withdraw their invitations quickly if you do not respond immediately. It would be an effective anti-spam tool to be able to see who has invited you to chat and to be able to flag that invitation as legitimate or as spam. We have a list of blocked contacts. The withdrawn invitations could be listed there, too.