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This page describes an enhancement to the DFDL language, the Daffodil DFDL Layering extension, enabling DFDL schemas using this extension to describe data formats in such a way as to enable algorithmic computations of CRCs, Checksums, Parity bits, etc. These are checked when parsing, to insure data validity and/or well-formedness, and are recomputed and incorporated into the data infoset when unparsing data.
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