It’s strange. When you visit a Google Group and are not logged into your
Google Account (if you even have one) you might get the impression that you
cannot join that group. If you’re already a member of such a group, you’ve
perhaps noticed that you can unsubscribe from it using a
<groupname>+email@example.com email address. At first I
thought replacing “unsubscribe” with “subscribe” would allow me to join
<groupname>, but for some reason Google didn’t stick to that pattern. Instead it’s
Why such a link isn’t shown on each group page is beyond me, but at least it is hidden in the the documentation.