Hi Nina,

I think that a couple edits about responding to an invitation would be useful.

Responding to an invitation to join a group
On this page - https://groups.io/helpcenter/membersmanual/1/joining-groups/responding-to-an-invitation-to-join-a

Add a final bullet to say: If you do not already have a Groups.io account, you will receive an email from Groups.io asking you to confirm your subscription. 

And: 

In  https://groups.io/helpcenter/membersmanual/1/joining-groups/responding-to-a-confirm-your-subscription-message, 

It lists everything except what happens if you are responding to an invitation.

 

By the very specificity of the rest of the list, not having the Invite one on suggests that this doesn't happen for an invitation. And of course, it does!

Frances