In the document for bitOrder at http://redmine.ogf.org/dmsf_files/13309, section 3.2 states that there are only 3 valid combinations of bitOrder and byteOrder and other combinations should produce a schema definition error. I created a test with byteOrder of 'bigEndian' and bitOrder of 'leastSignificantBitFirst' but the test parses without errors.

See test 'test_bigEndianLeastFirst' in daffodil-test/src/test/scala-debug/edu/illinois/ncsa/daffodil/section05/simple_types/TestSimpleTypes2.scala and daffodil-test/src/test/resources/edu/illinois/ncsa/daffodil/section05/simple_types/BitOrder.tdml