The MIB's DESCRIPTION for cucsLicenseSourceFileId is only the auto-generated stub 'Cisco UCS license:SourceFile:id managed object property', but the 'id' property name together with its SnmpAdminString type tell us this column, on one individual license file entry recorded under a license source, holds the id as UCS Manager's data model defines it, exposed here as a read-only SNMP value (read-only). The id is the unique identifier UCS Manager assigns to this license file entry within the license source's internal bookkeeping, distinct from the filename itself. Two license files with the same filename uploaded at different times would still be distinguishable here by different id values.