One of the things he mentions here is that some sites don't have a cached link at all - it may be because they're explicitly telling Google not to cache the pag

One of the things he mentions here is that some sites don't have a cached link at all - it may be because they're explicitly telling Google not to cache the page. You can do that using the noarchive tag, which looks like this: <meta name="robots" content="noarchive" />