Question on "Invoiced Amount" field on Agreements form/window in Oracle Project Billing

I work for a commercial construction company.  We are on EBS 11.5.10.2.  So we are very much projects oriented.  We have contracts with most all of our customers for their construction projects.  On most contracts we do have retention involved.  So, for example, if we have done $1,000,000 of work in the past month, and the contract calls for 10% retention, what we will actually bill the customer is for $900,000 (and what the customer will pay us is $900,000).  The other $100,000 is withheld retention, which will eventually get billed to the customer and paid when it gets billed. 

On the Agreements form,  what I see as "Invoiced Amount" turns out to be the sum of what was billed to the customer plus the withheld (not yet billed) retention.  So in my example above, I would see an "Invoiced Amount" = $1,000,000.