Currently the Specification has IN, OUT and INOUT Parameters defined separately to the SQLExpression. Given that the 
philosophy is NOT to parse the SQLExpression, then the use of such parameters is only of relevance to Stored Procedures 
and hence the nature of the expression MUST be known before submission. I would suggest removing such specific 
parameters as they can be supplied as part of the SQLExpression.
It may still be necessary to have a generic SQLParameter ?.