2.2.11 Shared Workbooks
The shared workbook infrastructure is used to enable multiple users to make changes to a workbook at the same time as well as track changes that certain users make. A shared workbook contains a collection of users that currently have the document open and a set of revision logs (section 18.104.22.168) that contain the changes that users have made to the workbook. Each of these logs has a corresponding revision header associated with it and contains either a set of revision records (section 22.214.171.124) that have been made to the shared workbook because it has been shared or no revision records (section 126.96.36.199). A workbook is a shared workbook if and only if the user names stream (section 188.8.131.52) exists.
The following sections define terms used in this diagram.