Entitlement required: manageUserGroups (Manage users and groups), or manageAllUserGroups (Synchronize users and groups), or manageUserStandardGroups (Manage users and standard groups), or manageGroups (Manage all groups but not their members), or manageStandardGroups (Manage standard groups but not their members), or manageGroupMembers (Manage all group and their members), or manageStandardGroupMembers (Manage standard groups and their members).
Note: You only need one entitlement, but you can have more than one.

Restrictions per request: Up to 1,000 patch operations are allowed. The total number of "values" specified cannot exceed 1,000.

Limitations: If the group being patched has over 9,000 members, the "replace" operation on the "members" attribute is not supported and only the "eq" operator is allowed in the selection filter.

By default, an email is sent to each regular user member added and removed from the group. Federated user members do not get an email notification. The email templates for branding are at "notifications/user_management/group/{locale}/user_added_to_group_email.xml" and "notifications/user_management/group/{locale}/user_removed_from_group_email.xml". Pass in the themeId query parameter to brand the email templates for notifications.

The following example is a patch request to replace the group's displayName, remove a member, and add new members. Notice also that the example shows how you can specify the notifyType if you want to.
NotifyType is an optional attribute that denotes the notification type. If not present, the EMAIL notification is used.Specify NONE if no notification to affected users is required.