gbak v4 can't backup database in ODS <13

[hvlad]

1. Run Firebird 3
2. Try to backup database in ODS12 using gbak v4 or v5:

firebird>gbak -b -g inet://database.fdb backup.fbk -z
gbak:gbak version WI-V5.0.1.1333 Firebird 5.0
gbak:    Version(s) for database "inet://database.fdb"
        Firebird/Windows/AMD/Intel/x64 (access method), version "WI-V3.0.11.33666 Firebird 3.0"
        Firebird/Windows/AMD/Intel/x64 (remote server), version "WI-V3.0.11.33666 Firebird 3.0/tcp (FireWork)/P15:C"
        Firebird/Windows/AMD/Intel/x64 (remote interface), version "WI-V5.0.1.1333 Firebird 5.0/tcp (FireWork)/P15:C"
        on disk structure version 12.0
gbak: ERROR:table id 51 is not defined

[hvlad]

Relation 51 is RDB$PUBLICATIONS

[mrotteveel]

Isn't that entirely expected?

[hvlad]

Yes, sure.
I meant - newer gbak should be able to backup older database when connected to the corresponding (older) server