I'm having a back-and-forth argument with upper management regarding the issue of a borrower's preferred name instead of their legal full name. Can anyone direct me where I need to go to get backup documentation to support the argument?

Can anyone direct me where I need to go to get backup documentation to support the argument?

Your legal counsel. There should be a signed AKA document in file.

Thank you, I will contact counsel.

Curious where you're getting the 'full legal name'.
Also, what are you using this for?
If you're talking mortgages, you use the name as it appears on title. Nothing else matters.
As for deed prep, the bank has no say in how a person takes title.
Guess I'm not sure I see what the issue is here.