BarcodeControl.setChecksum

Sets the checksum mode. This can be set to one of:

Checksum Mode Value	Description
add	Adds the necessary checksum to the message to be encoded
auto	Chooses the barcode's default checksum behaviour
ignore	Doesn't check nor add a checksum
check	Requires the check character to be present in the message. This is a digitally generated digit appended to the end of the barcode to ensure the barcode is composed correctly

This value is supported by the Code 39, EAN 128, Post Net, Royal Mail and Intelligent Mail barcodes

Further documentation