Building lists, assigning drawing files

Drawing files that have not yet been assigned are displayed in the area at bottom right.

You can drag drawing files into the Building structure area.
The drawing file you drag into the Building structure area is attached below the level where you have positioned the cursor (highlighted in blue).
To select a range of drawing files: press the SHIFT key and click the first and last drawing file in the range. To select a series of non-adjacent files, press the CTRL key while clicking the drawing files.
To delete drawing files, drag them out of the Building structure area and release the mouse button.
You cannot move drawing files within the building structure. You have to delete them before you can re-insert them.