Answer:
From page 146, the document, not the pdf:
The record retention requirements (i.e., five-year requirement to retain relevant OFAC records; for blocked property, record retention for as long as blocked; once unblocked, records must be maintained for five years).
These are the records required by law, but they are "relevant" only if you have faced these circumstances. You might also keep records to indicate your procedures are followed, you verify that your OFAC software has been updated, etc.
First published on BankersOnline.com 1/11/10