When migrating files from a Windows server A to a Samba server B with the command 'net rpc share migrate files -S A -destination=B -acls -attrs -U administrator', some files that originally belong…

`use acl = yes` enables ACL support, but does not specifically handle unknown SIDs or their mapping.

`map group acls = yes` deals with how group ACLs are mapped, but not how *unknown* SIDs for users or groups are handled during migration.

The `force unknown acl user = yes` parameter tells Samba to map any unresolvable Windows SID (Security Identifier) found in an ACL to the `nobody` user and `nogroup` group on the Unix side. This prevents errors when migrating files with ACLs that refer to Windows users or groups not present in the Samba server's user/group mapping database.

`inherit acls = no` controls whether new files inherit ACLs from their parent directory, which is unrelated to mapping unknown SIDs during migration.