CFR Marfă 60 001Depoul Dej Triaj Depoul Dej Triaj

I never understood why some locos are classified as 60-xxxx and others as 060-DA-xxx.

In Romania for CFR the original classification was :
060-DA-000
060-EA-000
040-EC-000
040-DHC-000
040-DF-000
And so on, the first numbers are the number of axles, the letters are the tipe of loco, and the last is the number of order.
Afther CFR joined UIC they started to change to UIC standards.
So the new class is 60-0000-0 [class,number of order, autocontrol digit]

Aha, thank you very much.

Exactly.Even nowadays not all the locos have the UIC numbers.

Is it a museum loco?

Yes,and also a functional one