G - 4 DS6878 Product Reference Guide
Additional Capabilities
Regardless of how the signature is captured, the output signature image is de-skewed and right-side up.
A scanner that captures signatures automatically determines whether it is scanning a signature or a bar code. 
You can disable the signature capturing capability in a scanner.
Signature Boxes 
Figure G-3 illustrates the five acceptable signature boxes:
Figure G-3    
Acceptable Signature Boxes
Type 2: 
Type 5:
Type 7: 
Type 8: 
Type 9: