It is built in isn't it? This system for instance does the two things I mention, doesn't it? Are you sure yours doesn't too?
Click HELP at the bottom of this page and you can see the system help files and rules and so on. Even before you go to the actual rules the words you click from state "You must agree to these terms and rules before using the site."
If you log out of this system and attempt to register it shows you the same info I see on my site, at the end of the registration page it says:
As you can see, you can not join up at all unless you agree to the terms and rules. Until you do the SignUp button is not clickable.
Once you do it looks like this below...
...works fine for me. I suspect it does for you too really.
He has that built in and he feels what I am showing him is an add on when of course it isn't.
It is possible to turn it off via the board basics options... that shows that option like this of course:
If his user registered on a Xenforo system with this all setup he has already agreed the rules, and via Help the system stresses that all usage of the system means having to accept the rules. I'd say he probably has this covered.
You quoted just the first part of his message and said that he was talking of new registrations only, when the second part seems to say he wasn't. As do his later messages. I was responding to that in my reply to you.
Rule changes are of course pretty well covered already... as members agree to all future rule changes applying when they sign up and agree to the Xenforo set of supplied rules.
You state very clearly in the rules you make everyone agree to that "These terms may be changed at any time without notice." That makes it the members responsibility to keep an eye out for changes and to not use the system further if they don't accept any change that is made.
I really feel XenForo does this well. I believe ecko may simply be confused by the item he found in the resources area for use with a many years old version of XenForo.
No problem anyway.... I hope ecko can now see that anyone on his system who went past his current XenForo registration is totally covered by his rules....as he long as he has them turned on and making sense.
As you quite rightly say he can go and put up notices and so on if he wants to somehow cover this even more because he feels at some time in the past he didn't. Most systems, like mine, have always had every new registering member agree to the rules applying and to changes to them applying too, even back on vb it was the norm for us to have that.