To use the clipboard for input and output simply check the “Use clipboard for input and output” checkbox. When the Run button is pushed Really Simple Barcodes will attempt to accept the text data on the clipboard as a stream of barcode data, with the data for one barcode per line of the stream, eg
1001
1002
1003
1004
After the run the barcodes in text form will be on the clipboard, eg
1001
JLb9VbIfrv
1002
JLb9VJMVrv
1003
JLb99SrFrv
1004
JLb98c9frv
1005 JLb94crVrv
If the “Include original data in output” checkbox had been checked then the original data and the barcodes are both present on the clipboard, otherwise its just the barcodes.