[jgiger2014]

I used some google-fu and found that they left the RSVP page open from a different year and it can be found here: http://news.ycombinator.com/susrsvp

It seems to be a way to find if you are in early. However I got a message that I was not accepted, let's hope that was a mistake on that link!

[ac2u]

Yeah that could very much be a "record not found" error in disguise.