They are homophones not homonyms - normally I wouldn't be so pedantic, but in a thread around the idea of people having prove they know meanings/spellings/etc, it seems suitible.
Anyway, it just reiterates that, while funny, this method of captcha is pretty much useless.
edit: Why can't I use an apostrophe in a URL? HN seems to be stripping it out, so couldn't link to the Wikipedia page without a crufty "%27" showing up...
Interesting. It looks like ASCII character 27 is supposed to be valid within URIs according to both RFC 3986 and RFC 1738 (via [0]). Maybe it's a simple component of a system for preempting SQLi on other sites via links from HN?
[0] http://stackoverflow.com/questions/1547899/which-characters-...