When this item is checked margin indicators are included for many barcode types in the space allowed by the Margin Size value. There is special treatment for EAN and ITF barcodes, and for these types the setting of the Margin Size value is ignored.
For EAN codes the light margin indicators are < and > symbols, while for ITF codes the margin indicators are thick bars connecting the ends of the horizontal bearer bars. In both cases the specifications recommend the use of margin indicators, but their use is not mandatory.
More: