This page is served to you with this additional header:
Cache-Control: private
If you're getting it through an HTTP/1.1 proxy (or any thing that ressembles a shared cache), the proxy must not cache the content of the document. Note that this difffers from the proxy-revalidate directive, since in that latter case, the proxy is allowed (and should) keep the content of the page to issue a revalidation instead of a full-retreival.