XMI26 — 9.4.1 serialization of a property typed by a structured datatype

Table 9.4.1 states:

Choice of:
1. XMIObjectElement
2. XMIValueAttribute
3. Nested XMIValueElement
By default instances of structured datatypes are serialized as if they were classes, as described in 7.8.7. This can be overridden by the tag org.omg.xmi.flattenStructuredDatatypes in which case the values of the Properties are serialized as a single string separated (by default) by commas. The default separator can be overridden by the XMI org.omg.xmi.valueSeparator tag.

The flag org.omg.xmi.flattenStructuredDatatypes adds a layer of complexity for XMI interchange because tools need to handle effectively two different serialization strategies: flatten vs. structured.

The benefit of flattened structured datatype value serialization is questionable because its relevance has not been established in current practice and current implementations.

Suggest eliminating org.omg.xmi.flattenStructuredDatatypes.