While the Save form existing in earlier versions of the Inventory workbook, the full implementation of the form exists only in version 2.86 and later.
With version 2.86 and later the Save form will allow you to manage any reasonable number of backup copies of the Inventory.
At the top of the form are two text boxes that define the current file name and drive/folder path for the inventory as it is currently saved on your system.  You can edit these fields to change the name and location (use the "Browse" button for the location) of the working inventory file.  Clicking on the "Save Inventory" button on the bottom left of the form is the same as clicking the standard Excel File/Save (or File/Save as) menu command.
The backup capability is activated by clicking on the "Activate Backup for this File" check box (default is on).  The text boxes below the checkbox define the name and location of the backup file copy (or copies).  The list box below those fields contains the status of copies of the inventory.
The initial location of the backup files is the same folder as the working inventory file.  This location is less than ideal as it provides no protection should that drive become defective or corrupted.  So the first backup task should be to pick another location for the backup.  To do this click on the "Browse" button to right of the file location text box.  This will open a standard windows folder open window.  Browse to the drive and folder where you want to keep the backup.  You can create a new folder in this form.
When you click OK the new location path should appear in the "Backup File Path" text box.
You could just edit the path in the box, but if you make an error in entering the path the backup function will fail.  Better to use the Browse button
Next set the Backup File Count box to the number of copies of the inventory you want to manage for backup.  The Save Form will cycle through the files on each backup.  Therefore if you back up the inventory before you discover a serious error in the file you will have earlier backup copies to fall back to if necessary.
I have set the Backup File Count to 5, the Backup File Status window now shows the status of that number of backup copies.  I haven't performed a backup on this Inventory to this location so none of the copies exist as yet.
Now I have clicked on the Backup Inventory button, but I have not saved recent changes to this inventory.  The form will not allow you to backup a modified file, hence the Windows MessageBox display.  Before I can make a backup copy of this file I have to first save it by clicking on the Save Inventory button.
After saving the Inventory I clicked on the Backup Inventory button once more and a copy of the inventory has been placed in the Backup location.
The Backup File Status window now shows that one copy of the inventory now exists.
The file names for the individual backups are derived from the backup file name specified and the Backup File Count value.  Therefore you can leave the Backup File Name and the Save File Name the same without creating confusion as to which file is the working inventory and which is the backup.