This one might be easier to convey than the forum rules. The club requirements are as follows:
Must be 21+
Must play COD on the Xbox One
Pretty simple, right? Alcohol is in the logo, and there's no point in being in a club that you can't shoot faces with. That said, further expansion might be acceptable in the future.
If for some ridiculous reason you want to join but don't play COD on the Xbox One, I'll let the people decide. A hang around in a gaming club seems odd.
That's it. No practices, no forum post requirements, no BS. You wouldn't want to be in a club that you didn't participate in, right?