the partial close looks like an order was partially closed

and the remaining position is classified as split from...what ever order had part of its position closed out.

Did that make sense?

Thats my guess. But might not be completely accurate.

I assume your running an EA.

Look for those lines in the code and see what initiates them. Seems like something triggers a partial close of an order.
I don't write code but can understand what its doing and read it once its written.(80% of the time)

You could post the EA or send it to some one who does code, and see what they think.

But with out seeing first hand or looking at the code its hard to say.

Dave