Book Settings Dialog Box

Use the Document > Layout Book > Book Settings command
The Use Hierarchy option assigns IDs that reflect the position of the Layouts within the tree view hierarchy, including their position in Subsets. In this system, the Subsets can also receive an ID, which shows up as part of the ID assigned to each of its Layouts.
The Use Flat Layout Order option assigns IDs to all the Layouts of the Book. The ID assignment is performed in the Navigator from top to bottom regardless of the Layouts’ position in the hierarchy. In this case, Subsets will have no IDs. The Layout IDs will use the prefix and style you define here.
Note: You can access this panel easily from the Change Manager Palette.
if the Issue is closed, its Issue Date is listed here. The Issue Date for an open Issue is shown as “Work in Progress”.
Use Change ID (Default): Changes should appear on Layouts using their own global ID
Number by Revisions: Changes should appear on Layouts using the following ID: LayoutRevision ID + Suffix + numbering.