The TCV Root Index dialog displays the structures present in an index node. Index nodes are "shadow nodes" of folders; named as such because they share the same node index but a different node type. The node type "NID
TYPECONTENTS
TABLEINDEX" indicates a TCV Root index. This structure is undocumented, and it's format differs from version to version of Outlook. It essentially contains a stored off version of the previous 5 "views" of a folder. Using this node allows Outlook to at times avoid having to resort (or at least completely resort) a folder when viewing it.
Creating shadow nodes (as well as creating specific subnodes) is a common technique Outlook uses to save client implementation specific data in a PST file. Previous versions of Outlook do not know or care about the existance of such nodes, and ignore them. Future versions of Outlook can depend on a "version" field in such shadow nodes and act appropriately. The TCV Root Index is included as a good example of how and why such techniques may be used.

The top of the dialog contains the header of the root index node.
- bPlatform The platform on which this index node was created
- bVersion The version number of the structure shown in this dialog.
Below that is a tree control showing meta information about individual index nodes present. There are at max 5 indicies present. Each entry has the following fields:
- nidSub The subnode which contains the actual index data. The index data format is not documented, but it is essentially an ordered list of the rows in a TC, along with their version number.
- tagInst For multivalued sorts
- cRest The number of restrictions in the sort represented by this index
- dwRestF CRC of the restriction
- dwRestV CRC of the restriction
- lcid LCID of the machine this sort was saved/created on
- ssos The MAPI sort order set which defines this restriction. This is a fixed size allocation, room for 15 entries in the SOS.