Unsupported features of the DFDL Specification as of Daffodil 3.9.0 are listed below.

Note that this doesn't include just plain bugs in Daffodil, any of which could affect support for a feature, but rather the below is a list of features that there has been no intention to support as of this release.

DFDL Features

• Intersect and except operators [DAFFODIL-2379]
• defaulting of values for required elements - when unparsing [DAFFODIL-115]
• validation (when unparsing) [DAFFODIL-1582]
• byte-value entities (aka raw-byte entities)[DAFFODIL-258]
• nested prefix lengths [DAFFODIL-2030]
• XPath query-style expressions [DAFFODIL-1118]
• "type" component of DFDL infoset [DAFFODIL-182], [DAFFODIL-1852]
• "unionMemberSchema" component of DFDL infoset [DAFFODIL-1633]
• "valid" component of DFDL infoset [DAFFODIL-813]
• extended ICU symbol 'I' in calendarPattern [DAFFODIL-1462]
• floating elements in sequences [DAFFODIL-643]
• "form" attribute (note that "elementFormDefault" is supported) [DAFFODIL-2416]
• unicodeByteOrderMark (Note this has been removed from the DFDL Specification v1.0)
• bi-directional text (Note this has been removed from the DFDL Specification v1.0, but may return in a future version of the DFDL spec.)
• dfdl:contentLength() and dfdl:valueLength() with 'characters' units and variable-width encodings [DAFFODIL-1516]
• dfdl:outputValueCalc calling dfdl:valueLength() for string with dfdl:truncateSpecifiedLengthString 'yes' [DAFFODIL-1598]
• Statement order of evaluation not per DFDL spec. [DAFFODIL-1971]

XML Schema Features

• fixed [DAFFODIL-117]
• default [DAFFODIL-115] [DAFFODIL-1277]

Properties and Property Enumerations

• dfdl:lengthUnits 'characters' with dfdl:lengthKind 'prefixed' [DAFFODIL-2029]
• dfdl:binaryFloatRep="ibm390Hex" [DAFFODIL-244]
• dfdl:documentFinalTerminatorCanBeMissing="yes" [DAFFODIL-230]
• dfdl:encodingErrorPolicy="error" (Note: this is accepted, but behaves as "replace")[DAFFODIL-935]
• dfdl:floating="yes" [DAFFODIL-643]
• dfdl:lengthKind="endOfParent" [DAFFODIL-238]
• dfdl:nilKind="logicalValue" [DAFFODIL-201]
• dfdl:nilKind='literalValue' with dfdl:representation='binary' [DAFFODIL-638]
• dfdl:occursCountKind="stopValue", dfdl:occursStopValue [DAFFODIL-501]
• dfdl:utf16Width="variable" [DAFFODIL-551]
• dfdl:calendarObserveDST [DAFFODIL-521]
• dfdl:calendarCenturyStart [DAFFODIL-519]
• dfdl:escapeCharacterPolicy [DAFFODIL-2415]
• dfdl:encoding using CCSIDs [DAFFODIL-2000]
• dfdl:useNilForDefault [DAFFODIL-1412]

The above listings are derived from this DFDL Language New Features JIRA Report .