Thank you very much for reply! The board sent emails to notify an annual meeting and agenda with attachment of Proxy. I didn't pay attention to it because I think the board should send mails if it's a big deal.The email and agenda didn't say there would be an amendment. This annual meeting happened in mid-January 2012. I didn't know anything until I got the amendment which was delivered to me by two board members.
I hope I can request for "variance" as you said. However, I don't find this article in the HOA document.
Does Federal Fair Housing Act works for this? The articles obviously ban leasing rooms to unrelated individuals(single people).Does this violate civil rights for fair housing?