When you enter a group in the guest list, and you have permission to see the group's members, the group will expand and the members will then appear in the invitation as if you added each one separately. The group expansion will happen either immediately, after a short delay, or after the event is saved, depending on the size of the group.

A few things to note:

• After a group member list expands, the group address itself no longer appears in the invitation.
• If the group has another group as a member, the "nested" group expands in the calendar invitation only if you have appropriate access permissions.
• If you don't have permission to see the group's members list, the group does not expand in your invitation. You can still invite the group, but you won't be able to see the list of members, their schedules, or their invitation responses. Also, attendees receive an invitation to the group address that they can add to their calendars; however, they can't accept the invitation directly, as described below.

If the group's members list expands in an invitation, it's as if you invited each member of the group individually. Members can accept the invitations as usual with the Yes, Maybe, and No links in the invitation.

If the members list doesn't expand:

• The event is not automatically added to members' calendars. Events are only added to attendee calendars when attendees are explicitly listed in the invitation's Who list.
• Group members can't reply with Yes, Maybe, and No links. (They will see an error message if they click these links.) Instead, members can click Add to calendar in the top section of the invitation.

Whether you can expand a group's members list depends on the "who can view members" setting for the group. For example, the Announcement access setting allows only a group's owners and managers to view the members list, so only those users can expand the group's list of members in calendar invitations.

For a group created before the Google Groups for Business service was released (December 2009), edit its access settings as follows:

1. In your Admin console, click Groups.
2. Select the group in the list.
3. Do one of the following:
   • If the Google Groups for Business service is enabled, click Access settings. Then change the Who can view members? setting.
   • If the Google Groups for Business service is disabled, click Roles and permissions. Then, under Custom, change the Who can > View members list setting.

Once a group has been expanded, anyone who is invited to the event — even those who are not a member of the group — can see the expanded list. The expanded list looks like individual invitations, so there is no way for invitees to tell who is a member of a particular group.

No. Once a group's members list is expanded in a calendar invitation, it's no longer linked to the group's member list in your Groups service. Therefore, if you add or remove a member, you'll need to manually add or remove that member in the calendar invitation.

Note, however, that sharing a calendar with a group works differently: If you add or remove a member, access to the shared calendar is updated automatically to reflect the change in the members list.

When a group invitation expands to over 500 (100 for recurring events) people excluding duplicates, these restrictions take effect:

• Invitees do not see the full invitee list. (The threshold for this is actually smaller than 500.)
• Invitees can never modify the event or invite additional people to the event.
• Responses are not sent back to the event organizer and are not visible to other invitees.

When large groups are invited to an event, this behavior remains the same:

• Each member of the group gets the event on their own calendar.
• All invitees see changes made by the event organizer, except for changes to the invitee list.