UPCE1 6-Digit is another type of UPC-E barcode, similar to UPCE0 but with a different encoding pattern:

UPC-E: A 6-digit code that can be expanded to the full 12-digit UPC-A code.
UPCE1: Indicates a different encoding scheme from UPCE0. The ‘1’ in UPCE1 specifies an alternative compression method used to create the smaller UPC-E barcode.
Both UPCE0 and UPCE1 are used to encode the same type of information but use different methods to compress the data from the original UPC-A code.

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