There are 3 ways for creating transponder inventory.
1.You can manually enter
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transponder code.
2. Just scan Transponder if you have Self Service Centre (Checking Station).
3. Create Transponder list in txt or spreadsheet and copy it onto the clipboard.
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Click "Import" (You can save existing inventory by "Export" ing as well)
When you want to modify the number,
- untick "Active" 2. then modify
3. You can print Transponder Inventry Inventory too.