Yes you cant
You will need to create your spreadsheet of parts (minimum content will include the Category Number and Part Number, but Description is nice to have for clarity).
You will also want to add an additional column for Mark For Deletion, then any parts you want marked for deletion you just need to put a Y in that column.
You don't need to place an N for parts you don't want deleted. System Five will ignore any parts with a blank field or an N. Only parts with a Y in that column will be marked for deletion.
Once you have that spreadsheet built, it should look something like this.
Now we can data load the spreadsheet into System Five
Always do a backup before doing a data load in case something goes wrong and you need to restore your data to its state before the data load was done.
Now we should be ready to data load the parts marked for deletion.
Open System Five, click on Navigator, Inventory and Purchases, and Data Load.
Click on Part Load
Click on From File
Browse to your CSV file, select it and click Open.
Now click on each column and select the appropriate field from the drop down menu.
Category, Part Number, Description, and Marked For Deletion.
Now select the appropriate options. The settings I checked here should work in most instances.
Click Next again.
Now you are ready to perform the data load.
Click the Load button.
Click Yes to continue with the data load.
Click OK on the Information popup telling you to view the import log.
The import log will report any errors as well as which records were updated.
Click on View Log button to view this log and the import is done.
Now I would recommend checking a few of your inventory items to confirm that the parts were marked for deletion.