In response to a hack of the SAM.gov database, the government has decided to require new users and existing users seeking to update their registrations to provide a notarized letter.
Source: Hack Response: Notarized Letters Now Required for SAM.gov – SmallGovCon
SBA Affiliation Rules: Owner of One Share (of 120) Controlled Company – SmallGovCon
The owner of one share–out of 120–was presumed to control a company under the SBA’s multiple