5d)     Many of the attributes are inadequately defined or their meaning is deliberately left open. This partly defeats the purpose of the schema since it was designed specifically to be a format for exchanging usage data over grids but if interpretations of the attributes are different at different sites/grids, comparing exchanged data becomes complicated.  For example the Charge, Status, StartTime, EndTime, base properties claim that "The meaning of this charge will be site dependent", "the semantic meaning of the status is site dependent"  or "the value of this property may depend on the queuing system", etc.

Evaluation: Related to 5b); defer to mailing list; tighten semantics