Lestie - when I first started reading your "Bump", my poor nearsighted eyes thought they read "Burp"! I almost began this reply with "Excuse you"!

Anyway, I'm not sure if this is much help, because I am answering from a CRA context (I'm not a HMDA bank). Maybe this will prompt some discussion among the HMDA folks out there if anything similar exists in HMDA...
Section 345.42(a)(10)in the CRA Q&A's states "For loans originated or purchased in 1998 or later, if the institution cannot determine the borrower's street address, and does not know the census tract or block numbering area, the institution should report the borrower's state, county, MSA, if applicable,
and "NA," for "not available," in lieu of a census tract or block numbering area code."That's my stab at it. I hope it helps!