Unspecified, ambiguous location of "model-data" declaration

[rakhimov]

This is probably an error of omission. ambigious
The "model-data" container is not specified to be located within <opsa-mef></opsa-mef>
as the other containers (fault tree, etc.).
The model diagrams, BNF, and the original DTD have the "model-data" separate from the opsa-mef declaration.
If this is the intended specification,
the reasoning is not clear (why is it outside of "opsa-mef"?).
If it is an error omission,
should it be specified to be located just like other containers, i.e.,

opsa-mef = element opsa-mef { (fault-tree-defition | event-tree-definition | ... | model-data)* }

or should there be only one model-data per input file

opsa-mef = element opsa-mef { (fault-tree-definition | ...)*, model-data? }

[rakhimov]

XFTA accepts multiple model-data containers only within opsa-mef tag,
so I guess model-data was intended to be specified in schema just like other containers.