The MIB's DESCRIPTION for cucsLicenseSourceFileSig is only the auto-generated stub 'Cisco UCS license:SourceFile:sig managed object property', but the 'sig' property name together with its SnmpAdminString type tell us this column, on one individual license file entry recorded under a license source, holds the sig as UCS Manager's data model defines it, exposed here as a read-only SNMP value (read-only). The sig is the cryptographic signature embedded in the license file, which UCS Manager verifies before trusting the file's contents — a mismatched or missing signature is exactly what would produce a failed operState on the parent license file object. A tampered or corrupted license file would carry a signature that fails verification, causing UCS Manager to reject that file's grant entirely.