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The following properties are added to dfdl:sequence (with corresponding short forms)

• layerTransformation layerTransform (literal string or DFDL expression) - XSD NCNames - all reserved. In the future this may become extensible allowing QNames to be used.
• layerEncoding (literal string or DFDL expression)
• layerLengthKind - same values as dfdl:lengthKind
• layerTerminator (literal string or DFDL expression) - used with dfdl:layerLengthKind 'delimited'
• layerLength (literal string or DFDL expression) - used with dfdl:layerLengthKind 'explicit'
• layerLengthPattern - used with dfdl:layerLengthKind 'pattern'
• (TBD layer properties for when dfdl:layerLengthKind is 'prefixed' - such time as that is supported, if ever.)

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<daf:defineFormat name="base64Format" >
    <dfdl:format layerTransformationlayerTransform="base64" layerLengthKind="implicit" />
</dfdl:defineFormat>

These properties are only relevant to xs:sequence constructs, and so a dfdl:ref to a named format using these layer properties is only sensible from a dfdl:sequence or on an xs:sequence.

An xs:sequence where the layerTransformation layerTransform property is defined and non-empty string, is said to be a layered sequence.

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