lucy24 - 5:35 am on May 3, 2013 (gmt 0)
Please note that if your site automatically redirects mobile visitors coming to the desktop site to the mobile site, or vice versa, please be sure to configure your server to include the Vary HTTP header
Oops. I entirely missed that part, which means that about three-quarters of my previous post is wrong.
Did I say anything about caching? I think that was a different thread.
:: detour to (re)read google article ::
A common issue is redirecting users to irrelevant pages. For example, if a user visits example.com/article29, your website should redirect them to the equivalent mobile-optimized page, such as m.example.com/article29, instead of to the m.example.com homepage. This makes sure that incoming links and users' bookmarks work across devices
Also, we suggest giving users a way to override the redirect policy
I'll be darned. Just when you think everything g### says is utterly wrong, self-serving and can be safely ignored, they come out with something sensible. (Which is to say, something that people hereabouts have been saying too.)
we do not have any preference and recommend that webmasters consider their users
:: sitting on hands ::
They do seem to be saying that a redirect based on UA detection merits a Vary header. Wouldn't you think the robots could figure it out for themselves? All three Googlebot-Mobile versions use a pretty standard UA, the kind an ordinary RewriteRule would recognize.