Use this procedure to import the current layout as a sheet in the sheet set.
In some cases, you might have sheet drawings that do not conform to the NCS standard, and contain more than one sheet. When you create a sheet in the Drawing Explorer of AutoCAD Architecture toolset, only the first sheet in the sheet drawing is registered. To register other sheets as well, you may import them while the sheet drawing is open and the layout is displayed.
The sheet is added to the sheet subset. When you change to the Sheet Set view, and expand the sheet drawing containing the sheet, you can see that the additional sheet is now listed under the sheet drawing.