The current model for the DV_TEXT has language and
charset as mandatory attributes. Given that it is expected that in
almost all cases, all parts of an ENTRY, and most likely a
COMPOSITION will be in the same language and character encoding,
it would be preferable to make these attributes optional on
ELEMENT and CLUSTER, and mandatory higher up the inheritance tree.
The benefit will be a significant reduction in the number of coded
terms stored in data, which are repetitions of each other within
an ENTRY, and usually in a COMPOSITION.