What is 'PreCalc' in UpdateListItems?

Question

I see some examples with

    <Batch OnError="Continue" PreCalc="TRUE" . . .

and some that omit that attribute. I have seen zero examples that set it to FALSE.

What does this attribute do?

What would commend a value of TRUE?

What would commend a value of FALSE?

Is the default FALSE? Is it NULL?

Answer 1

Well, in my experience it turned out to be useful in successfully creating list items that have lookup columns to BCS External List, other wise you wouldn't be able to create one.