If you come to a meeting when it's been listed as full, it's usually not a problem. People who have reserved a spot may get sick or stuck at the office and can't come last minute. You're welcome to take their place. But, I'd like to keep the number at the meeting to no more than 20. As the group gets larger, it's more difficult for everyone to have adequate time to make their contribution to the discussion.
Therefore, if the meetup is full, please opt for the "waitlist" option on the RSVP. Plan to read the book for the meeting and meetup with let you know if/when a spot becomes open. More than likely, a spot will be made open a couple of days before the meeting.
You can also send me a message and we can try to work something out.