I just saw this question:
https://meta.stackexchange.com/questions/28625/whats-the-joke-in-the-stack-overflow-404-page-code
And it occurs to me this is likely to be the first of many; the polyglot joke is a little obscure. Could we add a link to the page that either points to the meta question where you ask for suggestions or the question I just linked to, in an effort to avoid users repeating the question every few days?