How to close the site so that users cannot register and only managers can create user accounts:

• Login to the ZMI, then navigate to the Plone instance
• Click the Security tab
• Scroll down, find and untick 'Acquire for Add portal member' and then tick only the Manager option to the right. Only managers will now be able to add new users
• This will now remove all 'Join' links throughout the Plone site.
• Now to add new users you need to log in (as a manager) and go to Portal Setup -> Users/Groups Administration